Mishra Rashmi Ranjan, Swain Manas Ranjan, Dangar Tushar Kanti, Thatoi Hrudayanath
Department of Biotechnology, MITS School of Biotechnology, Bhubaneswar 751024, Odisha, India.
Rev Biol Trop. 2012 Jun;60(2):909-24. doi: 10.15517/rbt.v60i2.4026.
Different groups of microorganisms are present in mangrove areas, and they perform complex interactions for nutrient and ecological balances. Since little is known about microbial populations in mangroves, this study analyzed the microbial community structure and function in relation to soil physico-chemical properties in Bhitarkanika, a tropical mangrove ecosystem in India. Spatial and seasonal fluctuations of thirteen important groups of microorganisms were evaluated from the mangrove forest sediments during different seasons, along with soil physico-chemical parameters. The overall microbial load (x10(5)cfu/g soil) in soil declined in the order of heterotrophic, free living N2 fixing, Gram-negative nitrifying, sulphur oxidizing, Gram-positive, spore forming, denitrifying, anaerobic, phosphate solubilizing, cellulose degrading bacteria, fungi and actinomycetes. Populations of the heterotrophic, phosphate solubilizing, sulphur oxidizing bacteria and fungi were more represented in the rainy season, while, Gram-negative, Gram-positive, nitrifying, denitrifying, cellulose decomposing bacteria and actinomycetes in the winter season. The pool size of most of other microbes either declined or maintained throughout the season. Soil nutrients such as N, P, K (Kg/ha) and total C (%) contents were higher in the rainy season and they did not follow any common trend of changes throughout the study period. Soil pH and salinity (mS/cm) varied from 6-8 and 6.4-19.5, respectively, and they normally affected the microbial population dynamics. Determination of bacterial diversity in Bhitarkanika mangrove soil by culture method showed the predominance of bacterial genera such as Bacillus, Pseudomonas, Desulfotomaculum, Desulfovibrio, Desulfomonas, Methylococcus, Vibrio, Micrococcus, Klebsiella and Azotobacter. Principal component analysis (PCA) revealed a correlation among local environmental variables with the sampling locations on the microbial community in the mangrove soil.
红树林地区存在不同的微生物群落，它们为养分和生态平衡进行着复杂的相互作用。由于对红树林中的微生物种群了解甚少，本研究分析了印度热带红树林生态系统布迪尔卡尼卡（Bhitarkanika）中微生物群落结构及其与土壤理化性质的关系。在不同季节，对红树林沉积物中的13个重要微生物群落以及土壤理化参数进行了空间和季节波动评估。土壤中的总微生物负荷（x10(5)cfu/g土壤）按以下顺序递减：异养菌、自由生活固氮菌、革兰氏阴性硝化菌、硫氧化菌、革兰氏阳性菌、芽孢形成菌、反硝化菌、厌氧菌、解磷菌、纤维素分解菌、真菌和放线菌。异养菌、解磷菌、硫氧化菌和真菌的数量在雨季更为常见，而革兰氏阴性菌、革兰氏阳性菌、硝化菌、反硝化菌、纤维素分解菌和放线菌在冬季更为常见。大多数其他微生物的数量在整个季节中要么减少要么保持稳定。土壤养分如氮、磷、钾（kg/ha）和总碳（%）含量在雨季较高，并且在整个研究期间它们没有遵循任何共同的变化趋势。土壤pH值和盐度（mS/cm）分别在6 - 8和6.4 - 19.5之间变化，它们通常会影响微生物种群动态。通过培养方法对布迪尔卡尼卡红树林土壤中的细菌多样性进行测定，结果表明芽孢杆菌属、假单胞菌属、脱硫肠状菌属、脱硫弧菌属、脱硫单胞菌属、甲基球菌属、弧菌属、微球菌属、克雷伯菌属和固氮菌属等细菌属占优势。主成分分析（PCA）揭示了当地环境变量与红树林土壤中微生物群落采样地点之间的相关性。
