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
目的:通过比较灶心土、赤石脂和禹余粮的热解特性及红外光谱相似度来探讨赤石脂、禹余粮替代灶心土的可行性。方法:热解特性研究采用热重差热综合热分析仪,取试样量(30±5)mg置于坩锅中,以10℃·min^(-1)的升温速率、流量60 m L...目的:通过比较灶心土、赤石脂和禹余粮的热解特性及红外光谱相似度来探讨赤石脂、禹余粮替代灶心土的可行性。方法:热解特性研究采用热重差热综合热分析仪,取试样量(30±5)mg置于坩锅中,以10℃·min^(-1)的升温速率、流量60 m L·min^(-1)的恒定流速通入模拟空气[N_2-O_2(4∶1)],从室温升至900℃。红外光谱试验采用溴化钾压片法,光谱分辨率4 cm^(-1),测量范围4 000~500 cm-1,扫描信号累加32次,所得数据经Omnic软件进行自动基线校正、平滑及纵坐标归一化。数据处理及图表绘制采用Origin 8.0软件和Omnic软件完成。结果:比较热解特性发现灶心土、赤石脂、禹余粮的热解特性均在400~600℃处出现一段失重台阶;但整体而言,赤石脂与禹余粮热解特性没有体现出灶心土热解特性的复杂性;通过红外光谱相似度数值得出,以灶心土作为对照,赤石脂与灶心土相似度数值较偏低,禹余粮与与灶心土相似度数值处于中等水平。结论:就热解特性及红外光谱相似度而言,禹余粮与灶心土相似性较好,可能较赤石脂更适用作灶心土的替代品,为相关中药炮制辅料的研究提供参考。展开更多
为了解褐黄血蜱唾液内细菌的种类和传播途径,本研究分别提取褐黄血蜱饱血、半饱血的蜱虫及其唾液细菌总DNA,以其为模板,以通用引物扩增细菌16S r DNA V3区,并对其进行序列分析。结果表明,唾液内优势菌序列分别与狡诈球菌、鞘氨醇单胞菌...为了解褐黄血蜱唾液内细菌的种类和传播途径,本研究分别提取褐黄血蜱饱血、半饱血的蜱虫及其唾液细菌总DNA,以其为模板,以通用引物扩增细菌16S r DNA V3区,并对其进行序列分析。结果表明,唾液内优势菌序列分别与狡诈球菌、鞘氨醇单胞菌属、立克次体、不可培养的细菌序列高度相似。虫体的优势菌序列与葡萄球菌属、立克次体、柯克斯体属的序列相似。饱血、半饱血蜱的唾液菌群结构存在一定差异,而蜱虫与其唾液的菌群结构差异很大。本研究表明褐黄血蜱唾液含条件致病菌,有经唾液传播疾病的潜在风险。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.
文摘为了解褐黄血蜱唾液内细菌的种类和传播途径,本研究分别提取褐黄血蜱饱血、半饱血的蜱虫及其唾液细菌总DNA,以其为模板,以通用引物扩增细菌16S r DNA V3区,并对其进行序列分析。结果表明,唾液内优势菌序列分别与狡诈球菌、鞘氨醇单胞菌属、立克次体、不可培养的细菌序列高度相似。虫体的优势菌序列与葡萄球菌属、立克次体、柯克斯体属的序列相似。饱血、半饱血蜱的唾液菌群结构存在一定差异,而蜱虫与其唾液的菌群结构差异很大。本研究表明褐黄血蜱唾液含条件致病菌,有经唾液传播疾病的潜在风险。
