Extracellular polymeric substances(EPS)are present externally to the microorganisms and play an important role in attachment and biofilm formation.These polymers possess antibacterial and antifouling activities.In thi...Extracellular polymeric substances(EPS)are present externally to the microorganisms and play an important role in attachment and biofilm formation.These polymers possess antibacterial and antifouling activities.In this study,the antifouling activity of EPS produced by an epibiotic bacterium associated with macroalga Ulva lactuca was assessed against fouling bacteria and barnacle larvae.Results indicate that the EPS isolated from the epibiotic bacterium inhibits the biofilm formation of the bacteria without much antibacterial activity.Also,the EPS reduced the settlement of barnacle larvae on the hard substrate under laboratory conditions.The epibiotic bacterium was identified as Kocuria flava based on 16 S rRNA gene sequencing.The EPS was further analysed using Fourier transform infrared(FT-IR),nuclear magnetic resonance(NMR)and X-ray diffraction(XRD)to understand the biochemical composition.NMR analysis revealed the presence of polysaccharides,proteins,acetyl amine and succinyl groups.Scanning electron microscope analysis indicated that the EPS consisted of aggregated and irregular sphere-shaped particles.展开更多
Fire-worms from the family Amphinomidae Lamark, 1818, act as a predator, scavenger and sedimentivores, in nearshore waters. This family has 146 valid species among them 18 numbers reported from Indian marine environme...Fire-worms from the family Amphinomidae Lamark, 1818, act as a predator, scavenger and sedimentivores, in nearshore waters. This family has 146 valid species among them 18 numbers reported from Indian marine environment and 11 reported from the Andaman waters. Among this family, genus <i style="font-family:" white-space:normal;"="">Choleia</i><span style="font-family:" white-space:normal;"=""> Lamark. 1818, reported 4 species and 1 subspecies from the Andaman waters. Among these the species </span><i style="font-family:" white-space:normal;"="">Chloeia flava pulchella</i><i style="font-family:" white-space:normal;"=""> </i><span style="font-family:" white-space:normal;"="">Baird, 1868</span><i style="font-family:" white-space:normal;"=""></i><span style="font-family:" white-space:normal;"="">was reported by Tampi and Rangarajan,</span><i style="font-family:" white-space:normal;"=""> </i><span style="font-family:" white-space:normal;"="">1964, but no detailed species description was found for this species. During the studies on continuous monitoring of the environmental parameter of nearshore waters of off South Andaman region, a specimen of </span><i style="font-family:" white-space:normal;"="">Chloeia flava pulchella</i><i style="font-family:" white-space:normal;"=""> </i><span style="font-family:" white-space:normal;"="">Baird, 1868, was collected. Later the cursory analysis for this specimen identification was revealed that the detailed description of this species found in this region was not available in the literature. So, the detailed taxonomic description was developed and presented in this article.</span>展开更多
Objective:To investigate the regulatory effects of two traditional mineral medicines(TMMs),Gypsum Fibrosum(Shigao,GF)and Terra Flava Usta(Zaoxintu,TFU),on gut-beneficial bacteria in mice,and preliminarily explore thei...Objective:To investigate the regulatory effects of two traditional mineral medicines(TMMs),Gypsum Fibrosum(Shigao,GF)and Terra Flava Usta(Zaoxintu,TFU),on gut-beneficial bacteria in mice,and preliminarily explore their mechanisms of action.Methods:Mice were randomly divided into 3 groups(n=10 per group):the control group(standard diet),the GF group(diet supplemented with 2%GF),and the TFU group(diet supplemented with 2%TFU).After 4-week intervention,16S rRNA gene sequencing was used to analyze the changes in the gut microbiota(GM).Scanning electron microscopy,in combination with coumarin A tetramethyl rhodamine conjugate and Hoechst stainings,was used to observe the bacteria and biofilm formation.Results:Principal coordinate analysis revealed that GF and TFU significantly altered the GM composition in mice.Further analysis revealed that GF and TFU affected different types of gut bacteria,suggesting that different TMMs may selectively modulate specific bacterial populations.For certain bacteria,such as Faecalibaculum and lleibacterium,both GF and TFU exhibited growth-promoting effects,implying that they may be sensitive to TMMs and that different TMMs can increase their abundance through their respective mechanisms.Notably,Lactobacillus reuteri,a widely recognized and used probiotic,was significantly enriched in the GF group.Random forest analysis identified lleibacterium valens as a potential indicator bacterium for TMMs'impact on GM.Further mechanistic studies showed that gut bacteria formed biofilm structures on the TFU surface.Conclusions:This study provides new insights into the interaction between TMMs and GM.As safe and effective natural clays,GF and TFU hold promise as potential candidates for prebiotic development.展开更多
基金The Deanship of Scientific Research of King Abdulaziz University under contract No.G-153-150-39。
文摘Extracellular polymeric substances(EPS)are present externally to the microorganisms and play an important role in attachment and biofilm formation.These polymers possess antibacterial and antifouling activities.In this study,the antifouling activity of EPS produced by an epibiotic bacterium associated with macroalga Ulva lactuca was assessed against fouling bacteria and barnacle larvae.Results indicate that the EPS isolated from the epibiotic bacterium inhibits the biofilm formation of the bacteria without much antibacterial activity.Also,the EPS reduced the settlement of barnacle larvae on the hard substrate under laboratory conditions.The epibiotic bacterium was identified as Kocuria flava based on 16 S rRNA gene sequencing.The EPS was further analysed using Fourier transform infrared(FT-IR),nuclear magnetic resonance(NMR)and X-ray diffraction(XRD)to understand the biochemical composition.NMR analysis revealed the presence of polysaccharides,proteins,acetyl amine and succinyl groups.Scanning electron microscope analysis indicated that the EPS consisted of aggregated and irregular sphere-shaped particles.
文摘Fire-worms from the family Amphinomidae Lamark, 1818, act as a predator, scavenger and sedimentivores, in nearshore waters. This family has 146 valid species among them 18 numbers reported from Indian marine environment and 11 reported from the Andaman waters. Among this family, genus <i style="font-family:" white-space:normal;"="">Choleia</i><span style="font-family:" white-space:normal;"=""> Lamark. 1818, reported 4 species and 1 subspecies from the Andaman waters. Among these the species </span><i style="font-family:" white-space:normal;"="">Chloeia flava pulchella</i><i style="font-family:" white-space:normal;"=""> </i><span style="font-family:" white-space:normal;"="">Baird, 1868</span><i style="font-family:" white-space:normal;"=""></i><span style="font-family:" white-space:normal;"="">was reported by Tampi and Rangarajan,</span><i style="font-family:" white-space:normal;"=""> </i><span style="font-family:" white-space:normal;"="">1964, but no detailed species description was found for this species. During the studies on continuous monitoring of the environmental parameter of nearshore waters of off South Andaman region, a specimen of </span><i style="font-family:" white-space:normal;"="">Chloeia flava pulchella</i><i style="font-family:" white-space:normal;"=""> </i><span style="font-family:" white-space:normal;"="">Baird, 1868, was collected. Later the cursory analysis for this specimen identification was revealed that the detailed description of this species found in this region was not available in the literature. So, the detailed taxonomic description was developed and presented in this article.</span>
基金Supported by Natural Science Foundation of China(No.31770540)the Key Research Program of Jiangsu Province(No.BE2018663)。
文摘Objective:To investigate the regulatory effects of two traditional mineral medicines(TMMs),Gypsum Fibrosum(Shigao,GF)and Terra Flava Usta(Zaoxintu,TFU),on gut-beneficial bacteria in mice,and preliminarily explore their mechanisms of action.Methods:Mice were randomly divided into 3 groups(n=10 per group):the control group(standard diet),the GF group(diet supplemented with 2%GF),and the TFU group(diet supplemented with 2%TFU).After 4-week intervention,16S rRNA gene sequencing was used to analyze the changes in the gut microbiota(GM).Scanning electron microscopy,in combination with coumarin A tetramethyl rhodamine conjugate and Hoechst stainings,was used to observe the bacteria and biofilm formation.Results:Principal coordinate analysis revealed that GF and TFU significantly altered the GM composition in mice.Further analysis revealed that GF and TFU affected different types of gut bacteria,suggesting that different TMMs may selectively modulate specific bacterial populations.For certain bacteria,such as Faecalibaculum and lleibacterium,both GF and TFU exhibited growth-promoting effects,implying that they may be sensitive to TMMs and that different TMMs can increase their abundance through their respective mechanisms.Notably,Lactobacillus reuteri,a widely recognized and used probiotic,was significantly enriched in the GF group.Random forest analysis identified lleibacterium valens as a potential indicator bacterium for TMMs'impact on GM.Further mechanistic studies showed that gut bacteria formed biofilm structures on the TFU surface.Conclusions:This study provides new insights into the interaction between TMMs and GM.As safe and effective natural clays,GF and TFU hold promise as potential candidates for prebiotic development.
