The effect of superheated steam(SHS)treatment on the quality characteristics of rape bee pollen were studied,and the efficiency of inactivation and inhibition of lipid oxidation were analyzed to investigate the differ...The effect of superheated steam(SHS)treatment on the quality characteristics of rape bee pollen were studied,and the efficiency of inactivation and inhibition of lipid oxidation were analyzed to investigate the differences between SHS and cobalt-60 isotope(^(60)Co)radiation treatment.The number of total plate count(TPC)and mold colonies(MC)remained within the limits of the standards after SHS treatment at 140℃for 2 min.Neither TPC nor MC were detected after^(60)Co irradiation.Peroxidase(POD)and polyphenol oxidase(PPO)activities significantly decreased with increasing temperature and duration of SHS,while^(60)Co radiation completely inactivated PPO.Compared to^(60)Co radiation,SHS treatment inhibited the deterioration of rape bee pollen by avoiding hydroperoxide production and lipid oxidation due to lack of oxygen.These results suggested SHS under 140℃for 2 min was the most suitable to inactivate the microorganisms and enzymes in rape bee pollen with minimal lipid oxidation.展开更多
Objective:To investigate the prevalence of microbial antigenic components of circulating immune complexes amongst grades of CD4 T lymphocyte counts in HIV sero positive and seronegative participants.Methods:Polyethele...Objective:To investigate the prevalence of microbial antigenic components of circulating immune complexes amongst grades of CD4 T lymphocyte counts in HIV sero positive and seronegative participants.Methods:Polyethelene glycol(PEG-600) and buffering methods of precipitation and dissociation of immune complexes was used to generate immune solution from sera of 100 HIV sero-positive and 100 HIV sero-negative participants.These were categorized into 3 grades based on CD4 count:】 500 cell/mm,200-499 cell/mm3 and 【200 cell/mm3.The immune solutions were assayed using membrane based immunoassay and antibody titration, along side its unprocessed serum for detection of various microbial antigens and or antibodies. CD4 T cell counts were estimated using Patec Cyflow SL-3 Germany.Results:Antigenic component of immune complexes of various infectious agents was detected in 99 and 70 HIV seropositive and HIV sero-negative participants,respectively.In group A,there were 10 HIV positive participants,including 4(40.0%) had circulating immune complexes(CICs) due to Salmonella species only:1(10.0%) due to Salmonella-Plasmodium falciparum(P.falciparum),SalmonellaP. falciparum-HCV and P.falciparum antigens,respectively.In group B,45(45.4%) HIV seropositive participants with CICs had CD4 T lymphocyte count between 200-499 cells/mm^3.Out of these,20(44.4%) had CICs due to Salmonella species only:9(20%) due to Salmonella-P. falciparum.In group C,there were 44(44.4%) HIV sero-positive participants,including 3(6.8%) due to Salmonella species only:24(54.4%) due to Salmonella-P.falciparum:2(4.5%) due to P. falciparum only.Conclusions:In HIV sero-positive participants,presence of heterogeneity of Salmonella species-P.falciparum antigens was highly incriminated in CD4 count depletion but not homogeneity of malaria parasites antigens.Malaria parasites antigens only were incriminated in CD4^+ count depletion amongst HIV sero-negative participants.Before taking any decision on the management of HIV-1-positive individuals,their malaria and Salmonella paratyphi status should be assessed,but not malaria status alone.展开更多
Objective:To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour.Methods:Defatted process.inoculums preparation,evaluation of bacterial growth,preparation of cooked a...Objective:To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour.Methods:Defatted process.inoculums preparation,evaluation of bacterial growth,preparation of cooked and hydrolyzed media and growth turbidity of tested bacteria were determined.Results:Two percent defatted flour was found to be suitable concentration for the growth of pathogenic bacteria:Escherichia coli(ATCC 25922)(E,coli),Pseudomonas aeruginosa(ATCC27853),Salmonella(NCTC 8385)and Shigella flexneri(ATCC 12022)(S.flexneri),while 3%defatted flour was suitable for Staphylococcus aureus(ATCC 25923)(S.aureus).E.coli(93±1)and S.flexneri(524±1)colony count were significantly(P≤0.05)greater in defatted flour without supplement than in supplemented medium.E.coli[(3.72×10~9±2)CFU/mL],S.aureus[(7.4×10~9±2)CFU/mL],S.flexneri[(4.03×10~9±2)CFU/mL]and Salmonella[(2.37×10~9±1)CFU/mL]in non-hydrolyzed sample were statistically(P≤0.05)greater than hydrolyzed one and commercial peptone agar.Colony count of Salmonella[(4.55≤10~9±3)CFU/mL],S.flexneri[(5.40≤10~9±3)CFU/mL]and Lyesria moncytogenes(ATCC 19116)[(5.4×10~9±3)CFU/mL]on raw defatted flour agar was significantly(P≤0.05)greater than cooked defatted flour and commercial peptone agar.Biomass of E.coli,S.aureus.Salmonella and Enterococcus faecalis in non-hydrolyzed defatted flour is highly increased over hydrolyzed defatted flour and commercial peptone broth.Conclusions:The defatted flour agar was found to be better microbial media or comparable with peptone agar.The substances in it can serve as sources of carbon,nitrogen,vitamins and minerals that are essential to support the growth of microorganisms without any supplements.Currently,all supplements of peptone agar are very expensive in the market.展开更多
Milk is very susceptible for growth and development of many microorganisms because it is rich in nutrients and has suitable condition. Thus, it is very vital to respect sanitary conditions at all stages of production ...Milk is very susceptible for growth and development of many microorganisms because it is rich in nutrients and has suitable condition. Thus, it is very vital to respect sanitary conditions at all stages of production and transport of raw milk. The objective of the present investigation was to determine the total bacterial, and acidity in raw milk from milk collection centers in Malayer and Nahavand cities. 52 milk samples were collected from 13 centers in summer 2012 and were analyzed according to standard methods. None of the raw milk samples under investigation, had superior or grade 1 quality. Only 7.7% of the samples were classified as raw milk with grade 2 quality and 92.3% were non-standard. The mean of microbial total count in base was 3.8 × 107 CFU/ml and average acidity in the samples was 0.163. The city of Tochqhaz and Aliabade-Damagh has the lowest and the highest microbial total count. In general the result of this study showed unsatisfactory conditions of milk in the milk collection centers of the Malayer and Nahavand cities.展开更多
Application of the computer image analysis for improving microbial viability assessment by plate count and fluorescence microscopy was investigated. Yeast cells were used as a model microorganism. The application of t...Application of the computer image analysis for improving microbial viability assessment by plate count and fluorescence microscopy was investigated. Yeast cells were used as a model microorganism. The application of the improved methods for the viability assessment of yeast cells after preservation by freezing and freeze-drying was demonstrated.展开更多
The infection control in surfaces of public toilets environment is a matter of great concern and a major challenge, especially during mass gatherings. The present study aimed to evaluate the antimicrobial efficacy of ...The infection control in surfaces of public toilets environment is a matter of great concern and a major challenge, especially during mass gatherings. The present study aimed to evaluate the antimicrobial efficacy of titanium dioxide nanoparticles coating on environmental surfaces of public toilets during Hajj time. A pilot study has been designed to evaluate the antimicrobial efficacy of titanium dioxide nanoparticles on the surfaces of public toilets. The results showed a significant reduction in colony-count of the test samples. Maximum average reduction count of test microbes of the seats and walls reached (99.7%) while that of the doors reached (99.1%) which was statistically significant (P value = 0.001). It was concluded that there was a marked effect of a mixed TiO2 coating on reducing the microbial count at the surfaces of public toilets environments. Further research on efficacy against specific organisms, intestinal parasites, fungi, viruses and bacteriophage is recommended.展开更多
A stretch of the modern hypersaline coastal plain of the Gulf of Cambay was chosen to examine the distribution of the microbial mat-related structures(MRS) on siliciclastic sediments in the intertidal and supratidal z...A stretch of the modern hypersaline coastal plain of the Gulf of Cambay was chosen to examine the distribution of the microbial mat-related structures(MRS) on siliciclastic sediments in the intertidal and supratidal zones.The abundance of MRS increases from the lower intertidal zone to the upper supratidal zone while the type of MRS records a systematic change.While the lower intertidal zone exhibits wrinkle structures,sieve-like surfaces and patchy ripples in places,the upper intertidal zone exhibits diverse MRS related to reduced current activity on the mat layer and intermittent exposure.MRS in the upper intertidal zone include wrinkle structures,sieve-like surfaces,gas domes,reticulated surfaces,multi-directional ripples,patchy ripples,rolled-up mat fragments,setulfs and occasional petee ridges and cracked mat surfaces.The lower supratidal zone is characterized by increased occurrence of petee ridges,gas domes and cracked mat surfaces compared to the upper intertidal zone.The upper supratidal zone is distinguished by the presence of abundant cracked mat surfaces,petee ridges,gas domes and wrinkle structures.The presence of cm-scale,disc-shaped microbial colonies(DMC) with a variety of internal structures is a unique feature of the Gulf of Cambay study area.While wrinkle structures occur in all the coastal zones,setulfs occur close to the boundary between the upper intertidal and lower supratidal zones.An attempt has been made to compare the distribution of MRS in this modern environment with those in the ~1.6 Ga Chorhat Sandstone of the Vindhyan Supergroup for high-resolution palaeoenvironmental interpretation.The upper part of the intertidal segment of the Chorhat Sandstone is distinguished from its lower part by the presence of abundant cracked mat surfaces,petee ridges and gas domes in the former,while wrinkle structures,Kinneyia,rolled-up mat fragments,patchy ripples and multi-directional ripples are equally abundant in both parts.The lower part of the intertidal segment of the Chorhat Sandstone is thus analogous to the upper intertidal zone of the modern Gulf of Cambay environment,while the upper part of the Chorhat intertidal segment reflects prolonged exposure close to the high tide line.The bottom-most part of the intertidal segment of the Chorhat Sandstone with fewer MRS corresponds to the lower intertidal zone at Cambay.Inferred disc-shaped microbial fossils within Vindhyan sandstones are analogous to the DMC found in the modern environment and these features do not have any biostratigraphic implication.展开更多
米酒曲中微生物种类多样,微生物之间的相互作用影响着米酒的风味与品质。该研究基于高通量测序技术分析了我国南方地区米酒曲中微生物菌群多样性,研究结果表明,雷尔氏菌属(Ralstonia)和魏斯氏菌属(Weissella)为东南组和中部组的共同优...米酒曲中微生物种类多样,微生物之间的相互作用影响着米酒的风味与品质。该研究基于高通量测序技术分析了我国南方地区米酒曲中微生物菌群多样性,研究结果表明,雷尔氏菌属(Ralstonia)和魏斯氏菌属(Weissella)为东南组和中部组的共同优势细菌属,东南组的优势细菌属为红球菌属(Rhodococcus)(14.6%),东南组中5个组的菌群结构在属水平上类似,表明米酒曲的菌群结构与地域环境有一定联系。根霉属(Rhizopus)在所有米酒曲样品中占绝对优势(80.98%~99.22%)。米酒曲中细菌菌落总数最高的为湖北省孝感地区的酒曲(8.21 lg CFU/g),霉菌孢子数最高的为广东佛山的酒曲(9.61 lg个/g),酵母菌菌落总数最高的为安徽省阜阳市地区的酒曲(10.02 lg CFU/g)。同时,筛选获得酒曲中优势菌株功能菌4株,将4株功能菌株接种强化米酒曲,结果表明同时接种商业酒曲和功能菌株(SG组)的酒曲糖化酶、蛋白酶活力分别提高至1583.4 U和776.13 U/g,SG组的酯类物质种类最多达到17种,并且SG组的醇类、酯类和烷烃类物质的含量均显著提高,分别达到了1021.94、1190.82、535.80μg/100 g,表明功能菌在米酒及米酒曲中应用潜力巨大。展开更多
As one of the most widely used assays in biological research,an enumeration of the bacterial cell colonies is an important but time-consuming and labor-intensive process.To speed up the colony counting,a machine learn...As one of the most widely used assays in biological research,an enumeration of the bacterial cell colonies is an important but time-consuming and labor-intensive process.To speed up the colony counting,a machine learning method is presented for counting the colony forming units(CFUs),which is referred to as CFUCounter.This cellcounting program processes digital images and segments bacterial colonies.The algorithm combines unsupervised machine learning,iterative adaptive thresholding,and local-minima-based watershed segmentation to enable an accurate and robust cell counting.Compared to a manual counting method,CFUCounter supports color-based CFU classification,allows plates containing heterologous colonies to be counted individually,and demonstrates overall performance(slope 0.996,SD 0.013,95%CI:0.97–1.02,p value<1e-11,r=0.999)indistinguishable from the gold standard of point-and-click counting.This CFUCounter application is open-source and easy to use as a unique addition to the arsenal of colony-counting tools.展开更多
Aiming at the shortcomings of the existing automatic colony counter, a set of algorithms based on the principle of image chromatic aberration to achieve colony identification is proposed, and a colony identification d...Aiming at the shortcomings of the existing automatic colony counter, a set of algorithms based on the principle of image chromatic aberration to achieve colony identification is proposed, and a colony identification device is developed on this basis. The colony identification method is mainly based on the fact that different kinds of colonies and different concentrations of the same kind of colonies have different light-absorbing characteristics, and the judgement of colony types and concentrations is achieved through the method of image processing. The main features of the developed colony recognition equipment are high working efficiency, short recognition and detection time, and the potential of mixed recognition ability of multiple colonies. Therefore, the identification method and equipment have good application and promotion value in agriculture, food, medicine and other industries.展开更多
针对菌落图像中小菌落易漏检的问题,提出了一种基于INC4-YOLO(you only look once)的计数方法,实现精准的菌落计数。采用带残差结构的Inception模块(Inception module with residual connection,IncRes)替换YOLOv5骨干网络中的Bottlenec...针对菌落图像中小菌落易漏检的问题,提出了一种基于INC4-YOLO(you only look once)的计数方法,实现精准的菌落计数。采用带残差结构的Inception模块(Inception module with residual connection,IncRes)替换YOLOv5骨干网络中的Bottleneck模块,以增强图像特征提取能力。从网络的浅层特征中引出一个小目标检测头,以增强算法在训练过程中对小菌落的注意力。分别在标注微生物自动识别数据集(annotated germs for automated recognition,AGAR)和真实菌落计数场景下对INC4-YOLO进行计数性能测试。实验结果表明,在AGAR测试集中,提出的算法在小菌落的平均百分比绝对值计数误差(mean absolute percentage error,MAPE)比其他先进目标检测算法降低了2%;真实菌落计数场景下,INC4-YOLO的MAPE相比YOLOv5降低了7%,表明该算法可帮助菌落计数设备实现精准计数。展开更多
基金supported by National Natural Science Foundations of China(32472396,31871861 and 31501548)The Apicultural Industry Technology System(NCYTI-43-KXJ17)The Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2015-IAR)。
文摘The effect of superheated steam(SHS)treatment on the quality characteristics of rape bee pollen were studied,and the efficiency of inactivation and inhibition of lipid oxidation were analyzed to investigate the differences between SHS and cobalt-60 isotope(^(60)Co)radiation treatment.The number of total plate count(TPC)and mold colonies(MC)remained within the limits of the standards after SHS treatment at 140℃for 2 min.Neither TPC nor MC were detected after^(60)Co irradiation.Peroxidase(POD)and polyphenol oxidase(PPO)activities significantly decreased with increasing temperature and duration of SHS,while^(60)Co radiation completely inactivated PPO.Compared to^(60)Co radiation,SHS treatment inhibited the deterioration of rape bee pollen by avoiding hydroperoxide production and lipid oxidation due to lack of oxygen.These results suggested SHS under 140℃for 2 min was the most suitable to inactivate the microorganisms and enzymes in rape bee pollen with minimal lipid oxidation.
文摘Objective:To investigate the prevalence of microbial antigenic components of circulating immune complexes amongst grades of CD4 T lymphocyte counts in HIV sero positive and seronegative participants.Methods:Polyethelene glycol(PEG-600) and buffering methods of precipitation and dissociation of immune complexes was used to generate immune solution from sera of 100 HIV sero-positive and 100 HIV sero-negative participants.These were categorized into 3 grades based on CD4 count:】 500 cell/mm,200-499 cell/mm3 and 【200 cell/mm3.The immune solutions were assayed using membrane based immunoassay and antibody titration, along side its unprocessed serum for detection of various microbial antigens and or antibodies. CD4 T cell counts were estimated using Patec Cyflow SL-3 Germany.Results:Antigenic component of immune complexes of various infectious agents was detected in 99 and 70 HIV seropositive and HIV sero-negative participants,respectively.In group A,there were 10 HIV positive participants,including 4(40.0%) had circulating immune complexes(CICs) due to Salmonella species only:1(10.0%) due to Salmonella-Plasmodium falciparum(P.falciparum),SalmonellaP. falciparum-HCV and P.falciparum antigens,respectively.In group B,45(45.4%) HIV seropositive participants with CICs had CD4 T lymphocyte count between 200-499 cells/mm^3.Out of these,20(44.4%) had CICs due to Salmonella species only:9(20%) due to Salmonella-P. falciparum.In group C,there were 44(44.4%) HIV sero-positive participants,including 3(6.8%) due to Salmonella species only:24(54.4%) due to Salmonella-P.falciparum:2(4.5%) due to P. falciparum only.Conclusions:In HIV sero-positive participants,presence of heterogeneity of Salmonella species-P.falciparum antigens was highly incriminated in CD4 count depletion but not homogeneity of malaria parasites antigens.Malaria parasites antigens only were incriminated in CD4^+ count depletion amongst HIV sero-negative participants.Before taking any decision on the management of HIV-1-positive individuals,their malaria and Salmonella paratyphi status should be assessed,but not malaria status alone.
基金supported by the University of Gondar:General Director.Research & Community Service Core Process,Grant NO:UOG/Budget/no.6215
文摘Objective:To investigate and optimize microbial media that substitute peptone agar using brebra seed defatted flour.Methods:Defatted process.inoculums preparation,evaluation of bacterial growth,preparation of cooked and hydrolyzed media and growth turbidity of tested bacteria were determined.Results:Two percent defatted flour was found to be suitable concentration for the growth of pathogenic bacteria:Escherichia coli(ATCC 25922)(E,coli),Pseudomonas aeruginosa(ATCC27853),Salmonella(NCTC 8385)and Shigella flexneri(ATCC 12022)(S.flexneri),while 3%defatted flour was suitable for Staphylococcus aureus(ATCC 25923)(S.aureus).E.coli(93±1)and S.flexneri(524±1)colony count were significantly(P≤0.05)greater in defatted flour without supplement than in supplemented medium.E.coli[(3.72×10~9±2)CFU/mL],S.aureus[(7.4×10~9±2)CFU/mL],S.flexneri[(4.03×10~9±2)CFU/mL]and Salmonella[(2.37×10~9±1)CFU/mL]in non-hydrolyzed sample were statistically(P≤0.05)greater than hydrolyzed one and commercial peptone agar.Colony count of Salmonella[(4.55≤10~9±3)CFU/mL],S.flexneri[(5.40≤10~9±3)CFU/mL]and Lyesria moncytogenes(ATCC 19116)[(5.4×10~9±3)CFU/mL]on raw defatted flour agar was significantly(P≤0.05)greater than cooked defatted flour and commercial peptone agar.Biomass of E.coli,S.aureus.Salmonella and Enterococcus faecalis in non-hydrolyzed defatted flour is highly increased over hydrolyzed defatted flour and commercial peptone broth.Conclusions:The defatted flour agar was found to be better microbial media or comparable with peptone agar.The substances in it can serve as sources of carbon,nitrogen,vitamins and minerals that are essential to support the growth of microorganisms without any supplements.Currently,all supplements of peptone agar are very expensive in the market.
文摘Milk is very susceptible for growth and development of many microorganisms because it is rich in nutrients and has suitable condition. Thus, it is very vital to respect sanitary conditions at all stages of production and transport of raw milk. The objective of the present investigation was to determine the total bacterial, and acidity in raw milk from milk collection centers in Malayer and Nahavand cities. 52 milk samples were collected from 13 centers in summer 2012 and were analyzed according to standard methods. None of the raw milk samples under investigation, had superior or grade 1 quality. Only 7.7% of the samples were classified as raw milk with grade 2 quality and 92.3% were non-standard. The mean of microbial total count in base was 3.8 × 107 CFU/ml and average acidity in the samples was 0.163. The city of Tochqhaz and Aliabade-Damagh has the lowest and the highest microbial total count. In general the result of this study showed unsatisfactory conditions of milk in the milk collection centers of the Malayer and Nahavand cities.
文摘Application of the computer image analysis for improving microbial viability assessment by plate count and fluorescence microscopy was investigated. Yeast cells were used as a model microorganism. The application of the improved methods for the viability assessment of yeast cells after preservation by freezing and freeze-drying was demonstrated.
文摘The infection control in surfaces of public toilets environment is a matter of great concern and a major challenge, especially during mass gatherings. The present study aimed to evaluate the antimicrobial efficacy of titanium dioxide nanoparticles coating on environmental surfaces of public toilets during Hajj time. A pilot study has been designed to evaluate the antimicrobial efficacy of titanium dioxide nanoparticles on the surfaces of public toilets. The results showed a significant reduction in colony-count of the test samples. Maximum average reduction count of test microbes of the seats and walls reached (99.7%) while that of the doors reached (99.1%) which was statistically significant (P value = 0.001). It was concluded that there was a marked effect of a mixed TiO2 coating on reducing the microbial count at the surfaces of public toilets environments. Further research on efficacy against specific organisms, intestinal parasites, fungi, viruses and bacteriophage is recommended.
文摘A stretch of the modern hypersaline coastal plain of the Gulf of Cambay was chosen to examine the distribution of the microbial mat-related structures(MRS) on siliciclastic sediments in the intertidal and supratidal zones.The abundance of MRS increases from the lower intertidal zone to the upper supratidal zone while the type of MRS records a systematic change.While the lower intertidal zone exhibits wrinkle structures,sieve-like surfaces and patchy ripples in places,the upper intertidal zone exhibits diverse MRS related to reduced current activity on the mat layer and intermittent exposure.MRS in the upper intertidal zone include wrinkle structures,sieve-like surfaces,gas domes,reticulated surfaces,multi-directional ripples,patchy ripples,rolled-up mat fragments,setulfs and occasional petee ridges and cracked mat surfaces.The lower supratidal zone is characterized by increased occurrence of petee ridges,gas domes and cracked mat surfaces compared to the upper intertidal zone.The upper supratidal zone is distinguished by the presence of abundant cracked mat surfaces,petee ridges,gas domes and wrinkle structures.The presence of cm-scale,disc-shaped microbial colonies(DMC) with a variety of internal structures is a unique feature of the Gulf of Cambay study area.While wrinkle structures occur in all the coastal zones,setulfs occur close to the boundary between the upper intertidal and lower supratidal zones.An attempt has been made to compare the distribution of MRS in this modern environment with those in the ~1.6 Ga Chorhat Sandstone of the Vindhyan Supergroup for high-resolution palaeoenvironmental interpretation.The upper part of the intertidal segment of the Chorhat Sandstone is distinguished from its lower part by the presence of abundant cracked mat surfaces,petee ridges and gas domes in the former,while wrinkle structures,Kinneyia,rolled-up mat fragments,patchy ripples and multi-directional ripples are equally abundant in both parts.The lower part of the intertidal segment of the Chorhat Sandstone is thus analogous to the upper intertidal zone of the modern Gulf of Cambay environment,while the upper part of the Chorhat intertidal segment reflects prolonged exposure close to the high tide line.The bottom-most part of the intertidal segment of the Chorhat Sandstone with fewer MRS corresponds to the lower intertidal zone at Cambay.Inferred disc-shaped microbial fossils within Vindhyan sandstones are analogous to the DMC found in the modern environment and these features do not have any biostratigraphic implication.
文摘米酒曲中微生物种类多样,微生物之间的相互作用影响着米酒的风味与品质。该研究基于高通量测序技术分析了我国南方地区米酒曲中微生物菌群多样性,研究结果表明,雷尔氏菌属(Ralstonia)和魏斯氏菌属(Weissella)为东南组和中部组的共同优势细菌属,东南组的优势细菌属为红球菌属(Rhodococcus)(14.6%),东南组中5个组的菌群结构在属水平上类似,表明米酒曲的菌群结构与地域环境有一定联系。根霉属(Rhizopus)在所有米酒曲样品中占绝对优势(80.98%~99.22%)。米酒曲中细菌菌落总数最高的为湖北省孝感地区的酒曲(8.21 lg CFU/g),霉菌孢子数最高的为广东佛山的酒曲(9.61 lg个/g),酵母菌菌落总数最高的为安徽省阜阳市地区的酒曲(10.02 lg CFU/g)。同时,筛选获得酒曲中优势菌株功能菌4株,将4株功能菌株接种强化米酒曲,结果表明同时接种商业酒曲和功能菌株(SG组)的酒曲糖化酶、蛋白酶活力分别提高至1583.4 U和776.13 U/g,SG组的酯类物质种类最多达到17种,并且SG组的醇类、酯类和烷烃类物质的含量均显著提高,分别达到了1021.94、1190.82、535.80μg/100 g,表明功能菌在米酒及米酒曲中应用潜力巨大。
基金This research was funded by a VPR Special Research Grant entitled Potential of a Site-Specific DNA Interstrand Crosslink.
文摘As one of the most widely used assays in biological research,an enumeration of the bacterial cell colonies is an important but time-consuming and labor-intensive process.To speed up the colony counting,a machine learning method is presented for counting the colony forming units(CFUs),which is referred to as CFUCounter.This cellcounting program processes digital images and segments bacterial colonies.The algorithm combines unsupervised machine learning,iterative adaptive thresholding,and local-minima-based watershed segmentation to enable an accurate and robust cell counting.Compared to a manual counting method,CFUCounter supports color-based CFU classification,allows plates containing heterologous colonies to be counted individually,and demonstrates overall performance(slope 0.996,SD 0.013,95%CI:0.97–1.02,p value<1e-11,r=0.999)indistinguishable from the gold standard of point-and-click counting.This CFUCounter application is open-source and easy to use as a unique addition to the arsenal of colony-counting tools.
文摘Aiming at the shortcomings of the existing automatic colony counter, a set of algorithms based on the principle of image chromatic aberration to achieve colony identification is proposed, and a colony identification device is developed on this basis. The colony identification method is mainly based on the fact that different kinds of colonies and different concentrations of the same kind of colonies have different light-absorbing characteristics, and the judgement of colony types and concentrations is achieved through the method of image processing. The main features of the developed colony recognition equipment are high working efficiency, short recognition and detection time, and the potential of mixed recognition ability of multiple colonies. Therefore, the identification method and equipment have good application and promotion value in agriculture, food, medicine and other industries.
文摘针对菌落图像中小菌落易漏检的问题,提出了一种基于INC4-YOLO(you only look once)的计数方法,实现精准的菌落计数。采用带残差结构的Inception模块(Inception module with residual connection,IncRes)替换YOLOv5骨干网络中的Bottleneck模块,以增强图像特征提取能力。从网络的浅层特征中引出一个小目标检测头,以增强算法在训练过程中对小菌落的注意力。分别在标注微生物自动识别数据集(annotated germs for automated recognition,AGAR)和真实菌落计数场景下对INC4-YOLO进行计数性能测试。实验结果表明,在AGAR测试集中,提出的算法在小菌落的平均百分比绝对值计数误差(mean absolute percentage error,MAPE)比其他先进目标检测算法降低了2%;真实菌落计数场景下,INC4-YOLO的MAPE相比YOLOv5降低了7%,表明该算法可帮助菌落计数设备实现精准计数。
