In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)compost...In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)compost.The effects of inoculation on physical and chemical parameters,ammonia and hydrogen sulfide release,nitrogen form and sulfur compound content change and physical-chemical properties during nitrogen and sulfur conversion were studied.The results showed that inoculation of TNB and TSOB increased the temperature,pH,OM degradation,C/N ratio and germination index(GI)of compost.Compared with the control treatment(CK),the addition of inoculants reduced the release of NH_(3) and H_(2)S,and transformed them into nitrogen and sulfur compounds,the hydrolysis of polymeric ferrous sulfate was promoted,resulting in relatively high content of sulfite and sulfate.At the same time,the physical and chemical properties of SS have a strong correlation with nitrogen and sulfur compounds.展开更多
To obtain thermotolerant mutants of G. oxydans, which can enhance the transformation rate of L-sorbose to 2-Keto-L-gulonate （2-KLG） at 33℃ in a two-step process of vitamin C manufacture, ion beam was used as a muta...To obtain thermotolerant mutants of G. oxydans, which can enhance the transformation rate of L-sorbose to 2-Keto-L-gulonate （2-KLG） at 33℃ in a two-step process of vitamin C manufacture, ion beam was used as a mutation source. Gluconobacter oxydans GO and Bacillus megaterium B0 were used in this study. The original strain Gluconobacter oxydans GO was mutated by the heavy ion implantation facility at the Institute of Plasma Physics, Chinese Academy of Sciences. Several mutants including Gluconobacter oxydans GI13 were isolated and cocultured with Bacillus megaterium B0 at 33℃ in shaking flasks. The average transformation rate of the new mixed strain GI13-B0 in per gram-molecule reached 94.4% after seven passages in shaking flasks, which was increased by 7% when compared with the original mixed strain G0-B0 （Gluconobacter oxydans GO and Bacillus megaterium B0）. Moreover, the transformation rate of I13B0 was stable at 94% at temperatures ranging from 25℃ to 33℃, which would be of much value in reducing energy consumption in the manufacture of L-ascorbic acid, especially in the season of summer. To clarify some mechanism of the mutation, the specific activities of L-sorbose dehydrogenase in both GO and GI13 were estimated.展开更多
Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized ...Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized previously, the strains F-1, F-3 and F-10 represented Staphylococcus, Bacillus and Acetobacter spp., respectively. After checking various parameters for growth, acetic acid production rate was optimized further. Among the 3-starins analyzed here, the strain F-10 gave maximum acetic acid (7.0 g/100 ml) at 37°C in 2% ethanol concentration. The strain F-10 is capable of producing high yield of acetic acid at relatively high temperature, which is an ideal condition for vinegar production, which may reduce the water cooling expenses as well as the risk of contamination.展开更多
A total of 500 thermotolerant fermenting yeast isolates (100 from palm-wine and 400 from spoilt fruits) were screened for ethanol production at high temperatures. The best isolate that produced up to 4% ethanol from 1...A total of 500 thermotolerant fermenting yeast isolates (100 from palm-wine and 400 from spoilt fruits) were screened for ethanol production at high temperatures. The best isolate that produced up to 4% ethanol from 10% glucose at 45°C was selected for further experiments. The optimum pH for ethanol production by the isolate was pH 6 at both 30°C and 42°C. The isolate was identified as Pichia kudriavzevii base on the 18s ribosomal DNA. Ethanol production from 200 g/L cassava pulp using Simultaneous Saccharification and Fermentation (SSF) method at 30°C and 42°C by the isolate was investigated. At 30°C, an ethanol concentration of 30 g/L was produced. This represents an ethanol yield of 0.15 g/g of cassava pulp and 58.8% of the theoretical yield. However at 42°C, the concentration of ethanol produced increased to 42 g/L representing an ethanol yield of 0.21 g/g of cassava pulp and 82.4% of the theoretical yield. The isolate produced slightly higher ethanol than the two typed strains NCYC 587 and NCYC 2791 at 42°C. This isolate has a good potential to be used for commercial bioethanol production since it can produce ethanol at 45°C without a significant drop in ethanol yield.展开更多
Metagenomic approaches are recently used for searching novel open reading frames （ORFs） coding enzymes employed in pharmaceutical, rood industries, etc. In this study, a metagenornic library was constructed from Chu...Metagenomic approaches are recently used for searching novel open reading frames （ORFs） coding enzymes employed in pharmaceutical, rood industries, etc. In this study, a metagenornic library was constructed from Chumathang hotspring sediment DNA. The library consisted of approximately 9,000 clones and was screened for protease activity. A clone exhibiting protease activity was identified and named CHprol. Sequencing of CHprol revealed that the ORF encoded a functional protein of 363 amino acids belonging to peptidase S8-S53 superfamily. CHprol shared 41% sequence similarity with a reported protease （subtilase family） and 35 % structural similarity with the crystal structure of Pro-Tk sps. of Thermococcus kodarkaenasis. In silico modeling the 3D structure of CHprol showed that it has two beta sheets, 10 alpha helices and 11 strands. Catalytic triad prediction implied CHprol to be a serine protease. The optimum temperature and pH of the purified protease were found to be 80 ℃ and 11.0, respectively. The enzyme was active at 5 % concentration of hydrogen peroxide and retained 60 % of activity at 10 % concentration. The thermotolerant, alkalophilic and oxidant stable properties of the protease make it a potential can- didate for biotechnological applications.展开更多
Objective: To evaluate temporal and spatial nutrient level regimes and thermotolerant coliform counts (TTC) as water quality determinants.Methods: The annual research was conducted from November 2014 to November 2015,...Objective: To evaluate temporal and spatial nutrient level regimes and thermotolerant coliform counts (TTC) as water quality determinants.Methods: The annual research was conducted from November 2014 to November 2015, over six sampling seasons at seven selected sites within the greater City of Mostar, the regional centre of Herzegovina. For determination of physical, chemical and microbiological parametres Standard Methods for the Examination od Water and Wastewater (APHA, 1995) were used.Results: The results indicate that nutrient levels are within prescribed limits, although they are raised along a longitudinal gradient, correlating with wastewater outlests. The water quality was found to be within the I/II class during all tested seasons, suggesting that the river Neretva is in good condition and meets the requirements of the EU Water Framework Directive (2000).The TTC counts, however indicate a high level of contamination, due to communal wastewater outlets.Conclusions: Raised nutrient and bacterial contents are noted in high number of waterways,worldwide. Hence a more thorough investigation from epidemiological and toxicological aspects is warranted for setting the water quality standards.展开更多
Primary oil recovery is the first stage of hydrocarbon production in which a reservoir uses its natural energy to force hydrocarbon to its wellbore.Secondary oil recovery comes to play when hydrocarbons can no longer ...Primary oil recovery is the first stage of hydrocarbon production in which a reservoir uses its natural energy to force hydrocarbon to its wellbore.Secondary oil recovery comes to play when hydrocarbons can no longer be further produced by natural means.The purpose of secondary recovery is to maintain reservoir pressure so as to displace hydrocarbons toward the wellbore.Both primary and secondary recovery processes cannot displace more than 50%of the available hydrocarbons in a reservoir.The remaining hydrocarbons are further recovered through Tertiary/Enhanced Oil Recovery techniques.According to literature,microbial enhanced oil recovery has been identified as a tertiary method used to improve the efficiency of hydrocarbon production from reservoirs.Microbial enhanced oil recovery is a feasible reservoir technology,which has not been widely used in the oil and gas industry owing to the attainment of the requisite reservoir conditions such as temperature within which microbes can thrive.Literature has shown that thermotolerant microbes can withstand optimum temperatures of 50e90℃,while deep and ultra-deep hydrocarbon reservoir temperatures are often above 100℃.This study identifies some isolated thermotolerant microbes from a sandstone reservoir that can withstand temperatures as high as 110℃via conventional methods and molecular analysis.The identified thermotolerant petroleum microbes:Bacillus amyloliquefaciens(A)and Bacillus nealsonii(B)were used to enhance oil recovery from a reservoir.The results showed that the microbial species A and B at a confined pressure of 3.0 MPa and temperature of 27℃,gave 46.4%and 48.6%oil recoveries,respectively,which is comparably higher than the value(26.9%)obtained for the water flooded samples.At temperatures of 80,90,100,110 and 120℃,the oil recovery results show that the recovery factor(55.2%e64.1%)of species B were higher compared to the range(46.7e57.5%)recorded for species A.At the onset of the core flooding experiments,there was an initial increment in oil recovery factor as the temperature increased from 80 to 110℃,whereas,it remained constant within 110e120℃.This trend coincides with the drop in the thermal resistance exhibited by the microbes when exposed to such conditions.The cumulative oil production from the commercial Eclipse simulation closely matched those of the experiment results,whereas,the slight difference can be attributed to the adjustment of the simulation input parameters.The experimental results show that species B can be used to enhance oil recovery at reservoir temperature conditions above 100℃.展开更多
Tomato(Solanum lycopersicum)is an important fruit and vegetable crop in worldwide.The fertility of tomato reproductive organs can be dramatically decreased when ambient temperatures rise above 35°C,reducing tomat...Tomato(Solanum lycopersicum)is an important fruit and vegetable crop in worldwide.The fertility of tomato reproductive organs can be dramatically decreased when ambient temperatures rise above 35°C,reducing tomato fruit yield.It is necessary to identify transcription factors(TFs)and target genes involved in heat stress response(HSR)signaling cascades in tomato flower buds to improve tomato plant thermotolerance.In this study,we profiled genes expressed in three developmental stages of tomato flower buds.Red and turquoise modules for heat stress(HS)were identified through gene co-expression network analysis,and the genes within these modules were enriched in HS-related pathways.By focusing on the TFs in the two modules,we identified several novel HSR-related TFs,including SlWRKY75,SlMYB117,and SlNAM.Furthermore,homology analysis illustrated a conserved signaling cascade in tomato.Lastly,we identified and experimentally validated four HSF-regulated genes,namely SlGrpE,SlERDJ3A,SlTIL,and SlPOM1,that likely modulate thermotolerance in plants.These results provide a high-resolution atlas of gene expression during tomato flower bud development under HS conditions,which is a valuable resource for uncovering potential regulatory networks associated with the HSR in tomato.展开更多
The Clp/Hsp100 family,part of the ATPase associated with various cellular activities(AAA+)superfamily,includes caseinolytic peptidase B(ClpB),a highly conserved protein found in bacteria,fungi,protozoa,and plants.Nota...The Clp/Hsp100 family,part of the ATPase associated with various cellular activities(AAA+)superfamily,includes caseinolytic peptidase B(ClpB),a highly conserved protein found in bacteria,fungi,protozoa,and plants.Notably,ClpB is present in all ESKAPE pathogens:Enterococcus faecium,Staphylococcus aureus,Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa,and Enterobacter spp.ClpB plays a crucial role in reactivating and disaggregating proteins,enabling pathogens to survive under host-induced stress and conferring thermotolerance to bacterial cells.Infections caused by ESKAPE pathogens are particularly challenging due to their resistance to broad-spectrum antibiotics and biofilm formation,posing a significant global health threat as they are often multidrug-resistant,extensively drug-resistant,and pan-drug-resistant.Given its absence in human cells and its essential role in bacterial survival under stress,ClpB is a promising target for antimicrobial therapy.Targeting Hsp100 family proteins could lead to the development of novel antifungal and antiprotozoal treatments.This review explores the function of ClpB in the survival of ESKAPE pathogens and the protozoan Plasmodium falciparum.Relevant research findings were compiled using academic databases,and data analysis was performed using Clustal Omega Multiple Sequence Alignment and Boxshade tools.展开更多
Rice(Oryza sativa L.)is essential for global food security,but faces increasing threats from extreme weather.High temperatures during the grain-filling stage lower rice yields and quality(Wada et al.,2019).Studies hav...Rice(Oryza sativa L.)is essential for global food security,but faces increasing threats from extreme weather.High temperatures during the grain-filling stage lower rice yields and quality(Wada et al.,2019).Studies have revealed the mechanisms by which heat stress impairs rice quality during the grain-filling stage,including the involvement of factors such as DG1(Qin et al.,2021b),Oscp Hsp70-2(Tabassum et al.,2020),and Osb ZIP58Β(Xu et al.,2020).展开更多
Water is indispensable at life. Resources in waters of the township of Abomey-Calavi are of national importance. The township of Abomey-Calavi is very close to the biggest plan of water Beninese lagoon: The Nokoué...Water is indispensable at life. Resources in waters of the township of Abomey-Calavi are of national importance. The township of Abomey-Calavi is very close to the biggest plan of water Beninese lagoon: The Nokoué lake. Besides, not only the waters of the ground water are consumed by the majority of the population from the traditional well, but also, the underground waters of the terminal continnental of the township of Abomey-Calavi are exploited intensely by the Society Nationnale of the Waters of Benin (SONEB) to nourish in drinking water in the townships of Abomey-Calavi, of Cotonou the biggest city of the country and Sèmè. The microbiological parameter followup (total coliforms, coliforms thermotolerants and enterrococcis) to the level of many traditional well and deep boring and some different points of Nokoué lake were the object of a treatment of data by the establishment of card of fecal contamination of waters natural of the region, that informs us on the quality of waters by the slant of a microbiological quality indication that calculates itself according to the method of Bovesse and Depelchin (1980). The survey of the microbiological contamination indication, succeeds to the establishment of seasonal cards of quality of waters.展开更多
The synthesis of an extracellular protease by Bacillus sp. HTS102—a wild strain recently isolated from the wool of Portuguese Merino ewes, was optimized. This protease is thermostable and particularly resistant to ha...The synthesis of an extracellular protease by Bacillus sp. HTS102—a wild strain recently isolated from the wool of Portuguese Merino ewes, was optimized. This protease is thermostable and particularly resistant to harsh environmental conditions—and appears to bear a unique ability to hydrolyze keratin-rich solid materials. Following a preliminary screening for the most relevant medium factors involved in processing, a fractional factorial design (2VI6-1) was applied to ascertain the effects of six relevant parameters—viz. yeast extract concentration, peptone level, inoculum size, stirring rate, temperature and pH. The concentrations of yeast extract and peptone, as well as the incubation temperature and pH were found to play significant roles;and the 2-factor interaction between yeast extract level and pH was also significant. A 2.2-fold increase in the overall level of protease synthesis was eventually attained, with the improved medium relative to the basal medium—which is noteworthy when compared with competing proteases and previous optimization efforts.展开更多
Many microorganisms can tolerate high-temperature ranges from 37°C - 45°C are called thermotolerant microorganisms. Eighteen such isolates containing various microorganisms were collected from the natural fe...Many microorganisms can tolerate high-temperature ranges from 37°C - 45°C are called thermotolerant microorganisms. Eighteen such isolates containing various microorganisms were collected from the natural fermented products of Bangladesh in summer for bioethanol production. Cultural, morphological, physiological, biochemical and genetical analysis were carried out under various physiological conditions. Among them, two thermotolerant strains Tari-6, isolated from the Tari (an overnight natural fermented palm juice at around 33°C - 40°C) and Pvt-1, isolated from the Pantavat (an overnight natural fermented rice soaked with tap water at around 35°C - 37°C), produced high amount of bioethanol, 7.5% (v/v) and 6.5% (v/v), respectively at 37°C. Furthermore, a partial 26S rDNA sequencing results confirmed that the Tari-6 and Pvt-1 encoded Pichia galeiformi and Pichia guilliermondii, respectively, and later one could grow well in media containing Xylose. Our results conclude that these two yeast strains are the potential candidates for bioethanol production.展开更多
This study aims to generate data which can be used as a potential starting point for the updating of the Philippine Water Quality Criteria and the determination of the true impact of land use to the fecal contaminatio...This study aims to generate data which can be used as a potential starting point for the updating of the Philippine Water Quality Criteria and the determination of the true impact of land use to the fecal contamination of the Pampanga River Basin (PRB), the largest subwatershed of Manila Bay. Levels of fecal indicator bacteria (FIB) were determined in the selected tributaries of the PRB, representing three land use categories, namely, the forest/woodland (control), agricultural and residential lands. FIB were quantified in order to investigate the potential contribution of the selected areas in the fecal contamination of the PRB. The study was conducted in 2021 covering March, May, June, July, and September to represent the dry (March and May) and wet (June, July, and September) seasons. Counts of FIB, namely thermotolerant coliform, E. coli, and enterococci were qualitatively correlated with the results of the ocular survey and key informant interview based on known fecal contributors and their relevant rainfall data. FIB counts of water bodies in the selected agricultural and residential land use categories had Geometric Mean (GM) counts that are statistically greater than those of bodies of water near the representative forest/woodland (control), and exceeded the acceptable GM limits for all FIB, regardless of the season. Notably, the GM values recorded for the waters near the selected forest/woodland (control) passed the water quality criteria for all measured FIB parameters for both seasons. Furthermore, enterococci levels in the control site were statistically lower during the wet season. These initial findings suggest that agricultural and residential land use categories could be major contributors to the unacceptable water quality of tributaries of the Pampanga River Basin. The prevalence of thermotolerant coliforms and E. coli was noted regardless of rainfall and land use, indicating these FIB may not be adequate as water quality indicators. With their ability to survive and persist in fecally contaminated sediments in water bodies and in nutrient-poor environments, enterococci could be more definitive indicators of fecal contamination and microbiological quality of environmental waters.展开更多
Vinegar production is seriously affected by the sensitivity of acetic acid bacteria (AAB) to high temperature, high ethanol concentrations, and high acetic acid concentrations. The aim of this study was to investigate...Vinegar production is seriously affected by the sensitivity of acetic acid bacteria (AAB) to high temperature, high ethanol concentrations, and high acetic acid concentrations. The aim of this study was to investigate the thermo-ethanol-acid tolerance characters of five AAB strains (VMA1, VMA5, VMA7, VMAM, VMAO) previously isolated from fermented mango alcohol and belonging to Gluconoacetobacter genera. As result, the five AAB strains exhibited good growth and acid production at temperatures up to 45°C;they could tolerate and produce acetic acid at ethanol concentrations up to 20% (v/v). In addition, the studied strains showed growth at acetic acid concentrations up to 4.5% (w/v). Strains VMA7 and VMAO showed the highest resistance properties: they demonstrated acid production at 50°C and VMAO could even grow at 60°C;they tolerated and produced acetic acid at 25% (v/v) ethanol concentration;they showed resistance to acetic acid concentrations up to 6% (w/v). Considering all these properties, the use of these strains would seriously contribute to improving the quality of the vinegar produced and help to reduce the cooling water feeds in vinegar production especially in hot countries in the context of global warming.展开更多
Heat stress (HS) caused by rapidly warming climate has become a serious threat to global food security.Rice (Oryza sativa L.) is a staple food crop for over half of the world’s population,and its yield and quality ar...Heat stress (HS) caused by rapidly warming climate has become a serious threat to global food security.Rice (Oryza sativa L.) is a staple food crop for over half of the world’s population,and its yield and quality are often reduced by HS.There is an urgent need for breeding heat-tolerant rice cultivars.Rice plants show various morphological and physiological symptoms under HS.Precise analysis of the symptoms(phenotyping) is essential for the selection of elite germplasm and the identification of thermotolerance genes.In response to HS,rice plants trigger a cascade of events and activate complex transcriptional regulatory networks.Protein homeostasis under HS is especially important for rice thermotolerance,which is affected by protein quality control,effective elimination of toxic proteins,and translational regulation.Although some agronomic and genetic approaches for improving heat tolerance have been adopted in rice,the molecular mechanisms underlying rice response to HS are still elusive,and success in engineering rice thermotolerance in breeding has been limited.In this review,we summarize HS-caused symptoms in rice and progress in heat-stress sensing and signal cascade research,and propose approaches for improving rice thermotolerance in future.展开更多
Plant leaves may emit a substantial amount of volatile organic compounds （VOCs） into the atmosphere, which include isoprene, terpene, alkanes, alkenes, alcohols, aldehydes, eters, esters and carboxylic acids. Furthe...Plant leaves may emit a substantial amount of volatile organic compounds （VOCs） into the atmosphere, which include isoprene, terpene, alkanes, alkenes, alcohols, aldehydes, eters, esters and carboxylic acids. Furthermore, most of these compounds actively participate in tropospheric chemistry. Great progresses have been made in linking emission of these compounds to climate. However, the VOCs emission function in plant is still not clear. Recently, some evidence has emerged that the production and the emission of VOCs, such as isoprene and monoterpenes, which account for 80% of total VOCs, exhibit plant protection against high temperatures. These increases in VOCs emissions could contribule in a significant way to plant thermotolerance. This perspective summarizes some latest literatures regarding the VOCs emission-dependent thermoprotection in plant species subjected to high temperature stress, presents the achievement in studies concerning plant VOCs emission-dependent thermotolerance, and then exhibits the proposed mechanisms of such plant thermotolerance. Finally open questions regarding the plant VOCs emission were shown, and the future researches were proposed.展开更多
Global warming threatens food security.Rice(Oryza sativa L.),a vital food crop,is vulnerable to heat stress,especially at the reproductive stage.Here we summarize putative mechanisms of high-temperature perception(via...Global warming threatens food security.Rice(Oryza sativa L.),a vital food crop,is vulnerable to heat stress,especially at the reproductive stage.Here we summarize putative mechanisms of high-temperature perception(via RNA secondary structure,the phyB gene,and phase separation)and response(membrane fluidity,heat shock factors,heat shock proteins,and ROS(reactive oxygen species)scavenging)in plants.We describe how rice responds to heat stress at different cell-component levels(membrane,endoplasmic reticulum,chloroplasts,and mitochondria)and functional levels(denatured protein elimination,ROS scavenging,stabilization of DNA and RNA,translation,and metabolic flux changes).We list temperature-sensitive genetic male sterility loci available for use in rice hybrid breeding and explain the regulatory mechanisms associated with some of them.Breeding thermotolerant rice species without yield penalties via natural alleles mining and transgenic editing should be the focus of future work.展开更多
High temperature is one of the major abiotic stresses that limit edible mushroom growth and development. The understanding of physiological alterations in response to heat stress and the corresponding mechanisms invol...High temperature is one of the major abiotic stresses that limit edible mushroom growth and development. The understanding of physiological alterations in response to heat stress and the corresponding mechanisms involved is vital for the breeding of heat-resistant edible mushroom strains. Although trehalose functions as a protectant against abiotic stresses in fungi, the putative role of trehalose in thermotolerance remains to be elucidated. In this study, we found heat stress inhibited the growth of two Pleurotus pulmonarius strains, heat-sensitive and less-sensitive, and the inhibition was more significant for the sensitive strain. Heat stress leads to the increase of lipid peroxidation and intracellular trehalose accumulation, with a higher level in the heat-sensitive strain, and this effect is independent of exogenous trehalose application. In addition, a lower concentration of exogenous trehalose application in sensitive strain than in less-sensitive strain was found to alleviate the inhibition of mycelium growth and further increase the intracellular trehalose concentration by heat stress. Thus, the protective effects of trehalose were more remarkable in the sensitive strain. The activities of intracellular trehalose metabolic enzymes, i.e., trehalose-6-phosphate synthase, trehalose phosphorylase and neutral trehalase, were determined, and our data indicated that the changes of these enzymes activities in the sensitive strain were more beneficial to accumulate trehalose than that in the less-sensitive strain.展开更多
Thermal adaptation plays a fundamental role in shaping the distribution and abundance of insects,and heat shock proteins（Hsps）play important roles in the temperature adaptation of various organisms.To better underst...Thermal adaptation plays a fundamental role in shaping the distribution and abundance of insects,and heat shock proteins（Hsps）play important roles in the temperature adaptation of various organisms.To better understand the temperature tolerance of the indigenous ZHJ2-biotype of whitefly Bemisia tabaci species complex,we obtained complete cDNA sequences for hsp90,hsp70,and hsp20 and analyzed their expression profiles under different high temperature treatments by real-time quantitative polymerase chain reaction.The high temperature tolerance of B.tabaci ZHJ2-biotype was determined by survival rate after exposure to different high temperatures for 1 h.The results showed that after 41°C heat-shock treatment for 1 h,the survival rates of ZHJ2 adults declined significantly and the estimated temperature required to cause 50% mortality（LT50）is 42.85°C for 1 h.Temperatures for onset（Ton）or maximal（Tmax）induction of hsps expression in B.tabaci ZHJ2-biotype were 35 and 39°C（or 41°C）.Compared with previous studies,indigenous ZHJ2-biotype exhibits lower heat temperature stress tolerance and Ton（or Tmax）than the invasive B-biotype.展开更多
基金This work was supported by the Wild Goose Array Special Projects(No.2023STYZ002)Heilongjiang Provincial Research Institute Project(Nos.2023SSKY001 and 2022SSKY003).
文摘In this study,high temperature thermotolerant nitrifying bacteria(TNB)and high temperature thermotolerant sulfide oxidizing bacteria(TSOB)were obtained from compost samples and inoculated into sewage sludge(SS)compost.The effects of inoculation on physical and chemical parameters,ammonia and hydrogen sulfide release,nitrogen form and sulfur compound content change and physical-chemical properties during nitrogen and sulfur conversion were studied.The results showed that inoculation of TNB and TSOB increased the temperature,pH,OM degradation,C/N ratio and germination index(GI)of compost.Compared with the control treatment(CK),the addition of inoculants reduced the release of NH_(3) and H_(2)S,and transformed them into nitrogen and sulfur compounds,the hydrolysis of polymeric ferrous sulfate was promoted,resulting in relatively high content of sulfite and sulfate.At the same time,the physical and chemical properties of SS have a strong correlation with nitrogen and sulfur compounds.
基金supported by the National Major Technologies R&D Program of China during the 10th Five-Year Plan Period (No. 2001BA302B)
文摘To obtain thermotolerant mutants of G. oxydans, which can enhance the transformation rate of L-sorbose to 2-Keto-L-gulonate （2-KLG） at 33℃ in a two-step process of vitamin C manufacture, ion beam was used as a mutation source. Gluconobacter oxydans GO and Bacillus megaterium B0 were used in this study. The original strain Gluconobacter oxydans GO was mutated by the heavy ion implantation facility at the Institute of Plasma Physics, Chinese Academy of Sciences. Several mutants including Gluconobacter oxydans GI13 were isolated and cocultured with Bacillus megaterium B0 at 33℃ in shaking flasks. The average transformation rate of the new mixed strain GI13-B0 in per gram-molecule reached 94.4% after seven passages in shaking flasks, which was increased by 7% when compared with the original mixed strain G0-B0 （Gluconobacter oxydans GO and Bacillus megaterium B0）. Moreover, the transformation rate of I13B0 was stable at 94% at temperatures ranging from 25℃ to 33℃, which would be of much value in reducing energy consumption in the manufacture of L-ascorbic acid, especially in the season of summer. To clarify some mechanism of the mutation, the specific activities of L-sorbose dehydrogenase in both GO and GI13 were estimated.
文摘Thermotolerant microorganisms were collected, identified and characterized under different physiological conditions from various rotten fruits in Bangladesh for vinegar production. Among the 15-isolates characterized previously, the strains F-1, F-3 and F-10 represented Staphylococcus, Bacillus and Acetobacter spp., respectively. After checking various parameters for growth, acetic acid production rate was optimized further. Among the 3-starins analyzed here, the strain F-10 gave maximum acetic acid (7.0 g/100 ml) at 37°C in 2% ethanol concentration. The strain F-10 is capable of producing high yield of acetic acid at relatively high temperature, which is an ideal condition for vinegar production, which may reduce the water cooling expenses as well as the risk of contamination.
文摘A total of 500 thermotolerant fermenting yeast isolates (100 from palm-wine and 400 from spoilt fruits) were screened for ethanol production at high temperatures. The best isolate that produced up to 4% ethanol from 10% glucose at 45°C was selected for further experiments. The optimum pH for ethanol production by the isolate was pH 6 at both 30°C and 42°C. The isolate was identified as Pichia kudriavzevii base on the 18s ribosomal DNA. Ethanol production from 200 g/L cassava pulp using Simultaneous Saccharification and Fermentation (SSF) method at 30°C and 42°C by the isolate was investigated. At 30°C, an ethanol concentration of 30 g/L was produced. This represents an ethanol yield of 0.15 g/g of cassava pulp and 58.8% of the theoretical yield. However at 42°C, the concentration of ethanol produced increased to 42 g/L representing an ethanol yield of 0.21 g/g of cassava pulp and 82.4% of the theoretical yield. The isolate produced slightly higher ethanol than the two typed strains NCYC 587 and NCYC 2791 at 42°C. This isolate has a good potential to be used for commercial bioethanol production since it can produce ethanol at 45°C without a significant drop in ethanol yield.
基金supported by Council of Scientific and Industrial Research(CSIR)New Delhi,Government of India(37(1545)/12/EMR-II)entitled‘‘Exploring Microbial DiversityMining Novel Hydrolases from Brackish Water Lakes of Ladakh Region by Metagenomic Approach.’’
文摘Metagenomic approaches are recently used for searching novel open reading frames （ORFs） coding enzymes employed in pharmaceutical, rood industries, etc. In this study, a metagenornic library was constructed from Chumathang hotspring sediment DNA. The library consisted of approximately 9,000 clones and was screened for protease activity. A clone exhibiting protease activity was identified and named CHprol. Sequencing of CHprol revealed that the ORF encoded a functional protein of 363 amino acids belonging to peptidase S8-S53 superfamily. CHprol shared 41% sequence similarity with a reported protease （subtilase family） and 35 % structural similarity with the crystal structure of Pro-Tk sps. of Thermococcus kodarkaenasis. In silico modeling the 3D structure of CHprol showed that it has two beta sheets, 10 alpha helices and 11 strands. Catalytic triad prediction implied CHprol to be a serine protease. The optimum temperature and pH of the purified protease were found to be 80 ℃ and 11.0, respectively. The enzyme was active at 5 % concentration of hydrogen peroxide and retained 60 % of activity at 10 % concentration. The thermotolerant, alkalophilic and oxidant stable properties of the protease make it a potential can- didate for biotechnological applications.
文摘Objective: To evaluate temporal and spatial nutrient level regimes and thermotolerant coliform counts (TTC) as water quality determinants.Methods: The annual research was conducted from November 2014 to November 2015, over six sampling seasons at seven selected sites within the greater City of Mostar, the regional centre of Herzegovina. For determination of physical, chemical and microbiological parametres Standard Methods for the Examination od Water and Wastewater (APHA, 1995) were used.Results: The results indicate that nutrient levels are within prescribed limits, although they are raised along a longitudinal gradient, correlating with wastewater outlests. The water quality was found to be within the I/II class during all tested seasons, suggesting that the river Neretva is in good condition and meets the requirements of the EU Water Framework Directive (2000).The TTC counts, however indicate a high level of contamination, due to communal wastewater outlets.Conclusions: Raised nutrient and bacterial contents are noted in high number of waterways,worldwide. Hence a more thorough investigation from epidemiological and toxicological aspects is warranted for setting the water quality standards.
文摘Primary oil recovery is the first stage of hydrocarbon production in which a reservoir uses its natural energy to force hydrocarbon to its wellbore.Secondary oil recovery comes to play when hydrocarbons can no longer be further produced by natural means.The purpose of secondary recovery is to maintain reservoir pressure so as to displace hydrocarbons toward the wellbore.Both primary and secondary recovery processes cannot displace more than 50%of the available hydrocarbons in a reservoir.The remaining hydrocarbons are further recovered through Tertiary/Enhanced Oil Recovery techniques.According to literature,microbial enhanced oil recovery has been identified as a tertiary method used to improve the efficiency of hydrocarbon production from reservoirs.Microbial enhanced oil recovery is a feasible reservoir technology,which has not been widely used in the oil and gas industry owing to the attainment of the requisite reservoir conditions such as temperature within which microbes can thrive.Literature has shown that thermotolerant microbes can withstand optimum temperatures of 50e90℃,while deep and ultra-deep hydrocarbon reservoir temperatures are often above 100℃.This study identifies some isolated thermotolerant microbes from a sandstone reservoir that can withstand temperatures as high as 110℃via conventional methods and molecular analysis.The identified thermotolerant petroleum microbes:Bacillus amyloliquefaciens(A)and Bacillus nealsonii(B)were used to enhance oil recovery from a reservoir.The results showed that the microbial species A and B at a confined pressure of 3.0 MPa and temperature of 27℃,gave 46.4%and 48.6%oil recoveries,respectively,which is comparably higher than the value(26.9%)obtained for the water flooded samples.At temperatures of 80,90,100,110 and 120℃,the oil recovery results show that the recovery factor(55.2%e64.1%)of species B were higher compared to the range(46.7e57.5%)recorded for species A.At the onset of the core flooding experiments,there was an initial increment in oil recovery factor as the temperature increased from 80 to 110℃,whereas,it remained constant within 110e120℃.This trend coincides with the drop in the thermal resistance exhibited by the microbes when exposed to such conditions.The cumulative oil production from the commercial Eclipse simulation closely matched those of the experiment results,whereas,the slight difference can be attributed to the adjustment of the simulation input parameters.The experimental results show that species B can be used to enhance oil recovery at reservoir temperature conditions above 100℃.
基金supported by grants from the National Natural Science Foundation of China(Grant No.32072571)the 111 Project(Grant No.B17043)the Construction of Beijing Science,and Technology Innovation and Service Capacity in Top Subjects(Grant No.CEFF-PXM2019_014207_000032)。
文摘Tomato(Solanum lycopersicum)is an important fruit and vegetable crop in worldwide.The fertility of tomato reproductive organs can be dramatically decreased when ambient temperatures rise above 35°C,reducing tomato fruit yield.It is necessary to identify transcription factors(TFs)and target genes involved in heat stress response(HSR)signaling cascades in tomato flower buds to improve tomato plant thermotolerance.In this study,we profiled genes expressed in three developmental stages of tomato flower buds.Red and turquoise modules for heat stress(HS)were identified through gene co-expression network analysis,and the genes within these modules were enriched in HS-related pathways.By focusing on the TFs in the two modules,we identified several novel HSR-related TFs,including SlWRKY75,SlMYB117,and SlNAM.Furthermore,homology analysis illustrated a conserved signaling cascade in tomato.Lastly,we identified and experimentally validated four HSF-regulated genes,namely SlGrpE,SlERDJ3A,SlTIL,and SlPOM1,that likely modulate thermotolerance in plants.These results provide a high-resolution atlas of gene expression during tomato flower bud development under HS conditions,which is a valuable resource for uncovering potential regulatory networks associated with the HSR in tomato.
文摘The Clp/Hsp100 family,part of the ATPase associated with various cellular activities(AAA+)superfamily,includes caseinolytic peptidase B(ClpB),a highly conserved protein found in bacteria,fungi,protozoa,and plants.Notably,ClpB is present in all ESKAPE pathogens:Enterococcus faecium,Staphylococcus aureus,Klebsiella pneumoniae,Acinetobacter baumannii,Pseudomonas aeruginosa,and Enterobacter spp.ClpB plays a crucial role in reactivating and disaggregating proteins,enabling pathogens to survive under host-induced stress and conferring thermotolerance to bacterial cells.Infections caused by ESKAPE pathogens are particularly challenging due to their resistance to broad-spectrum antibiotics and biofilm formation,posing a significant global health threat as they are often multidrug-resistant,extensively drug-resistant,and pan-drug-resistant.Given its absence in human cells and its essential role in bacterial survival under stress,ClpB is a promising target for antimicrobial therapy.Targeting Hsp100 family proteins could lead to the development of novel antifungal and antiprotozoal treatments.This review explores the function of ClpB in the survival of ESKAPE pathogens and the protozoan Plasmodium falciparum.Relevant research findings were compiled using academic databases,and data analysis was performed using Clustal Omega Multiple Sequence Alignment and Boxshade tools.
基金supported by the National Natural Science Foundation of China(32270250 and 32400202)National Science Foundation of Fujian Province of China(2022J02004)+1 种基金Fujian Provincial Science and Technology Key Project(2024NZ029027)China Postdoctoral Science Foundation(2022M712665)。
文摘Rice(Oryza sativa L.)is essential for global food security,but faces increasing threats from extreme weather.High temperatures during the grain-filling stage lower rice yields and quality(Wada et al.,2019).Studies have revealed the mechanisms by which heat stress impairs rice quality during the grain-filling stage,including the involvement of factors such as DG1(Qin et al.,2021b),Oscp Hsp70-2(Tabassum et al.,2020),and Osb ZIP58Β(Xu et al.,2020).
文摘Water is indispensable at life. Resources in waters of the township of Abomey-Calavi are of national importance. The township of Abomey-Calavi is very close to the biggest plan of water Beninese lagoon: The Nokoué lake. Besides, not only the waters of the ground water are consumed by the majority of the population from the traditional well, but also, the underground waters of the terminal continnental of the township of Abomey-Calavi are exploited intensely by the Society Nationnale of the Waters of Benin (SONEB) to nourish in drinking water in the townships of Abomey-Calavi, of Cotonou the biggest city of the country and Sèmè. The microbiological parameter followup (total coliforms, coliforms thermotolerants and enterrococcis) to the level of many traditional well and deep boring and some different points of Nokoué lake were the object of a treatment of data by the establishment of card of fecal contamination of waters natural of the region, that informs us on the quality of waters by the slant of a microbiological quality indication that calculates itself according to the method of Bovesse and Depelchin (1980). The survey of the microbiological contamination indication, succeeds to the establishment of seasonal cards of quality of waters.
文摘The synthesis of an extracellular protease by Bacillus sp. HTS102—a wild strain recently isolated from the wool of Portuguese Merino ewes, was optimized. This protease is thermostable and particularly resistant to harsh environmental conditions—and appears to bear a unique ability to hydrolyze keratin-rich solid materials. Following a preliminary screening for the most relevant medium factors involved in processing, a fractional factorial design (2VI6-1) was applied to ascertain the effects of six relevant parameters—viz. yeast extract concentration, peptone level, inoculum size, stirring rate, temperature and pH. The concentrations of yeast extract and peptone, as well as the incubation temperature and pH were found to play significant roles;and the 2-factor interaction between yeast extract level and pH was also significant. A 2.2-fold increase in the overall level of protease synthesis was eventually attained, with the improved medium relative to the basal medium—which is noteworthy when compared with competing proteases and previous optimization efforts.
文摘Many microorganisms can tolerate high-temperature ranges from 37°C - 45°C are called thermotolerant microorganisms. Eighteen such isolates containing various microorganisms were collected from the natural fermented products of Bangladesh in summer for bioethanol production. Cultural, morphological, physiological, biochemical and genetical analysis were carried out under various physiological conditions. Among them, two thermotolerant strains Tari-6, isolated from the Tari (an overnight natural fermented palm juice at around 33°C - 40°C) and Pvt-1, isolated from the Pantavat (an overnight natural fermented rice soaked with tap water at around 35°C - 37°C), produced high amount of bioethanol, 7.5% (v/v) and 6.5% (v/v), respectively at 37°C. Furthermore, a partial 26S rDNA sequencing results confirmed that the Tari-6 and Pvt-1 encoded Pichia galeiformi and Pichia guilliermondii, respectively, and later one could grow well in media containing Xylose. Our results conclude that these two yeast strains are the potential candidates for bioethanol production.
文摘This study aims to generate data which can be used as a potential starting point for the updating of the Philippine Water Quality Criteria and the determination of the true impact of land use to the fecal contamination of the Pampanga River Basin (PRB), the largest subwatershed of Manila Bay. Levels of fecal indicator bacteria (FIB) were determined in the selected tributaries of the PRB, representing three land use categories, namely, the forest/woodland (control), agricultural and residential lands. FIB were quantified in order to investigate the potential contribution of the selected areas in the fecal contamination of the PRB. The study was conducted in 2021 covering March, May, June, July, and September to represent the dry (March and May) and wet (June, July, and September) seasons. Counts of FIB, namely thermotolerant coliform, E. coli, and enterococci were qualitatively correlated with the results of the ocular survey and key informant interview based on known fecal contributors and their relevant rainfall data. FIB counts of water bodies in the selected agricultural and residential land use categories had Geometric Mean (GM) counts that are statistically greater than those of bodies of water near the representative forest/woodland (control), and exceeded the acceptable GM limits for all FIB, regardless of the season. Notably, the GM values recorded for the waters near the selected forest/woodland (control) passed the water quality criteria for all measured FIB parameters for both seasons. Furthermore, enterococci levels in the control site were statistically lower during the wet season. These initial findings suggest that agricultural and residential land use categories could be major contributors to the unacceptable water quality of tributaries of the Pampanga River Basin. The prevalence of thermotolerant coliforms and E. coli was noted regardless of rainfall and land use, indicating these FIB may not be adequate as water quality indicators. With their ability to survive and persist in fecally contaminated sediments in water bodies and in nutrient-poor environments, enterococci could be more definitive indicators of fecal contamination and microbiological quality of environmental waters.
文摘Vinegar production is seriously affected by the sensitivity of acetic acid bacteria (AAB) to high temperature, high ethanol concentrations, and high acetic acid concentrations. The aim of this study was to investigate the thermo-ethanol-acid tolerance characters of five AAB strains (VMA1, VMA5, VMA7, VMAM, VMAO) previously isolated from fermented mango alcohol and belonging to Gluconoacetobacter genera. As result, the five AAB strains exhibited good growth and acid production at temperatures up to 45°C;they could tolerate and produce acetic acid at ethanol concentrations up to 20% (v/v). In addition, the studied strains showed growth at acetic acid concentrations up to 4.5% (w/v). Strains VMA7 and VMAO showed the highest resistance properties: they demonstrated acid production at 50°C and VMAO could even grow at 60°C;they tolerated and produced acetic acid at 25% (v/v) ethanol concentration;they showed resistance to acetic acid concentrations up to 6% (w/v). Considering all these properties, the use of these strains would seriously contribute to improving the quality of the vinegar produced and help to reduce the cooling water feeds in vinegar production especially in hot countries in the context of global warming.
基金supported by the National Key Research and Development Program of China (2016YFD0101801)the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA24030201)the State Key Laboratory of Plant Genomics。
文摘Heat stress (HS) caused by rapidly warming climate has become a serious threat to global food security.Rice (Oryza sativa L.) is a staple food crop for over half of the world’s population,and its yield and quality are often reduced by HS.There is an urgent need for breeding heat-tolerant rice cultivars.Rice plants show various morphological and physiological symptoms under HS.Precise analysis of the symptoms(phenotyping) is essential for the selection of elite germplasm and the identification of thermotolerance genes.In response to HS,rice plants trigger a cascade of events and activate complex transcriptional regulatory networks.Protein homeostasis under HS is especially important for rice thermotolerance,which is affected by protein quality control,effective elimination of toxic proteins,and translational regulation.Although some agronomic and genetic approaches for improving heat tolerance have been adopted in rice,the molecular mechanisms underlying rice response to HS are still elusive,and success in engineering rice thermotolerance in breeding has been limited.In this review,we summarize HS-caused symptoms in rice and progress in heat-stress sensing and signal cascade research,and propose approaches for improving rice thermotolerance in future.
文摘Plant leaves may emit a substantial amount of volatile organic compounds （VOCs） into the atmosphere, which include isoprene, terpene, alkanes, alkenes, alcohols, aldehydes, eters, esters and carboxylic acids. Furthermore, most of these compounds actively participate in tropospheric chemistry. Great progresses have been made in linking emission of these compounds to climate. However, the VOCs emission function in plant is still not clear. Recently, some evidence has emerged that the production and the emission of VOCs, such as isoprene and monoterpenes, which account for 80% of total VOCs, exhibit plant protection against high temperatures. These increases in VOCs emissions could contribule in a significant way to plant thermotolerance. This perspective summarizes some latest literatures regarding the VOCs emission-dependent thermoprotection in plant species subjected to high temperature stress, presents the achievement in studies concerning plant VOCs emission-dependent thermotolerance, and then exhibits the proposed mechanisms of such plant thermotolerance. Finally open questions regarding the plant VOCs emission were shown, and the future researches were proposed.
基金supported by the National Natural Science Foundation of China(31630052,31788103)Chinese Academy of Sciences(XDB27010104,QYZDYSSW-SMC023,159231KYSB20200008)+1 种基金the National Key Research and Development Program of China(2016YFD0100604)the Shanghai Science and Technology Development(18JC1415000)。
文摘Global warming threatens food security.Rice(Oryza sativa L.),a vital food crop,is vulnerable to heat stress,especially at the reproductive stage.Here we summarize putative mechanisms of high-temperature perception(via RNA secondary structure,the phyB gene,and phase separation)and response(membrane fluidity,heat shock factors,heat shock proteins,and ROS(reactive oxygen species)scavenging)in plants.We describe how rice responds to heat stress at different cell-component levels(membrane,endoplasmic reticulum,chloroplasts,and mitochondria)and functional levels(denatured protein elimination,ROS scavenging,stabilization of DNA and RNA,translation,and metabolic flux changes).We list temperature-sensitive genetic male sterility loci available for use in rice hybrid breeding and explain the regulatory mechanisms associated with some of them.Breeding thermotolerant rice species without yield penalties via natural alleles mining and transgenic editing should be the focus of future work.
基金supported by the National Basic Research Program of China (2014CB138303)the earmarked fund for China Agriculture Research System (CARS20)
文摘High temperature is one of the major abiotic stresses that limit edible mushroom growth and development. The understanding of physiological alterations in response to heat stress and the corresponding mechanisms involved is vital for the breeding of heat-resistant edible mushroom strains. Although trehalose functions as a protectant against abiotic stresses in fungi, the putative role of trehalose in thermotolerance remains to be elucidated. In this study, we found heat stress inhibited the growth of two Pleurotus pulmonarius strains, heat-sensitive and less-sensitive, and the inhibition was more significant for the sensitive strain. Heat stress leads to the increase of lipid peroxidation and intracellular trehalose accumulation, with a higher level in the heat-sensitive strain, and this effect is independent of exogenous trehalose application. In addition, a lower concentration of exogenous trehalose application in sensitive strain than in less-sensitive strain was found to alleviate the inhibition of mycelium growth and further increase the intracellular trehalose concentration by heat stress. Thus, the protective effects of trehalose were more remarkable in the sensitive strain. The activities of intracellular trehalose metabolic enzymes, i.e., trehalose-6-phosphate synthase, trehalose phosphorylase and neutral trehalase, were determined, and our data indicated that the changes of these enzymes activities in the sensitive strain were more beneficial to accumulate trehalose than that in the less-sensitive strain.
基金supported by the National Basic R&D Program of China(2009CB119200)the National Natural Science Foundation of China(30800722)
文摘Thermal adaptation plays a fundamental role in shaping the distribution and abundance of insects,and heat shock proteins（Hsps）play important roles in the temperature adaptation of various organisms.To better understand the temperature tolerance of the indigenous ZHJ2-biotype of whitefly Bemisia tabaci species complex,we obtained complete cDNA sequences for hsp90,hsp70,and hsp20 and analyzed their expression profiles under different high temperature treatments by real-time quantitative polymerase chain reaction.The high temperature tolerance of B.tabaci ZHJ2-biotype was determined by survival rate after exposure to different high temperatures for 1 h.The results showed that after 41°C heat-shock treatment for 1 h,the survival rates of ZHJ2 adults declined significantly and the estimated temperature required to cause 50% mortality（LT50）is 42.85°C for 1 h.Temperatures for onset（Ton）or maximal（Tmax）induction of hsps expression in B.tabaci ZHJ2-biotype were 35 and 39°C（or 41°C）.Compared with previous studies,indigenous ZHJ2-biotype exhibits lower heat temperature stress tolerance and Ton（or Tmax）than the invasive B-biotype.
