Use of eco-friendly area specific salt tolerant bioinoculants is better alternatives to chemical fertilizer for sustainable agriculture in coastal saline soils. We isolated diverse groups of diazotrophic bacteria from coastal saline soils of different forest and agricultural lands in the Sundarbans, West Bengal, India, to study their effect on crop productivity in saline soils. Phenotypic, biochemical and molecular identifications of the isolates were performed. The isolates produced indole acetic acid, phosphatase, and solubilized insoluble phosphates. Sequence analysis of 16S rDNA identified the SUND_BDU1 strain as Agrobacterium and the strains SUND_LM2, Can4 and Can6 belonging to the genus Bacillus. The ARA activity, dinitrogen fixation and presence of nifH genes indicated they were diazotrophs. Field trials with these strains as bioinoculants were carried out during 2007-2009, with rice during August-December followed by Lady's finger during April-June. Microplots, amended with FYM inoculated with four bioinoculants individually were compared against sole FYM (5tha -1) and a sole chemical fertilizer (60:30:30kgha -1 NPK) treated plot. The strain Can6 was by far the best performer in respect of yield attributes and productivity of studied crops. © 2011 Elsevier GmbH.

SAGARMOY GHOSH

Microbiology

S BARUA

S TRIPATHI

A CHAKRABORTY

K CHAKRABARTI

Fulltext

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Microbiological Research

The influence of temporal and spatial variations on the microbial community composition was assessed in the unique coastal mangrove of Sundarbans using parallel 16S rRNA gene pyrosequencing. The total sediment DNA was extracted and subjected to the 16S rRNA gene pyrosequencing, which resulted in 117 Mbp of data from three experimental stations. The taxonomic analysis of the pyrosequencing data was grouped into 24 different phyla. In general, Proteobacteria were the most dominant phyla with predominance of Deltaproteobacteria, Alphaproteobacteria, and Gammaproteobacteria within the sediments. Besides Proteobacteria, there are a number of sequences affiliated to the following major phyla detected in all three stations in both the sampling seasons: Actinobacteria, Bacteroidetes, Planctomycetes, Acidobacteria, Chloroflexi, Cyanobacteria, Nitrospira, and Firmicutes. Further taxonomic analysis revealed abundance of micro-aerophilic and anaerobic microbial population in the surface layers, suggesting anaerobic nature of the sediments in Sundarbans. The results of this study add valuable information about the composition of microbial communities in Sundarbans mangrove and shed light on possible transformations promoted by bacterial communities in the sediments. © 2014, Springer Science+Business Media New York.

Microbial Ecology

Spatiotemporal Analysis of Bacterial Diversity in Sediments of Sundarbans Using Parallel 16S rRNA Gene Tag Sequencing

Salinity is a natural stressor, extensively limiting land use for agriculture in coastal regions throughout the world. Beside plant growth, salinity also has an impact on microbial activity and diversity. Saline habitats have a unique microbial population, adapted to such environment. Recent developments in soil microbiology have improved the potential of saline land use. This involves use of salt tolerant or halophilic bioinoculants to improve nutrient mobilization in saline soil thereby favoring plant growth. Microbial community structure in terrestrial saline habitats varied from halophilic archaea, Gram-negative, Gram-positive bacteria to photosynthetic cyanobacteria. Many of them have been artificially augmented and applied directly to saline soils to improve nutrient status of such soil. One of the most interesting findings in this field of research is spatial and temporal variation in microbial community structure, which was related to variation in salinity of the microenvironment. Modern methods of studying environmental microbiology involves culture independent molecular techniques, biomarker based and in situ activity analyses, which assisted to have a better and detailed look on microbiological process in coastal saline environments. This review aims to recollect findings related to microbiology of coastal saline soils, with special emphasis to studies related to development of bioinoculants compatible for agriculture in coastal saline environments. © Springer International Publishing Switzerland 2015. All rights reserved.

Halophiles: Biodiversity and Sustainable Exploitation

Site specific bioinoculants for sustainable agriculture in coastal saline soil

The effect of fluctuations of salinity in three different seasons on diazotrophic populations and N2 fixation in six mono cropped rice field soils of the coastal region of the Gangetic delta of West Bengal, India, was studied. The average pH, ECe, organic carbon and total nitrogen of the soils ranged from 4. 99-7. 08, 2. 02-19. 58 dSm-1, 4. 68-12. 03 g kg-1 and 0. 44-1. 70 g kg -1, respectively. The average log colony forming units of the bacterial populations and N2-fixation in the soils varied from 4. 61 to 5. 86 and 2. 74 to 4. 52 mg N2 fixed 50 ml -1 culture media respectively, with the lowest value recorded in summer. Recovery of microorganisms and N2- fixation gradually decreased with extraneous addition of NaCl in the culture media. All the eight isolates were Gram positive, spore and capsule formers. They could utilize glucose, sucrose, mannitol, starch, citrate and nitrate, and were catalase and gelatinase positive, but indole, methyl red and Vogues Proskauer reaction negative. The organisms produced alkaline reaction on TSI agar slant. The acetylene reduction assay of the isolates at 0 and 1% NaCl in the culture media were 4. 51-164. 52 and 1. 72-100. 6 nmole C2H4 ml-1 culture media in 72 h, respectively. The isolates could fix 2. 42-4. 45 and 2. 04-4. 08 mg N2 fixed 50 ml-1 culture media at 0 and 1% NaCl in the culture media respectively. 16S rDNA sequences of the isolates were similar to the species: Bacillus sp. isolate 28A, Bacillus sp. MOLA 87, Bacillus sp. By113 (B)Ydz-dh, Bacillus sp. PN13, Bacillus licheniformis strain RH101, Bacterium Antarctica 14, Bacillus sp. PN13 and Bacillus megaterium. © 2011 Association of Microbiologists of India.

Indian Journal of Microbiology

Studies on Non-Symbiotic Diazotrophic Bacterial Populations of Coastal Arable Saline Soils of India

Soil salinity is a serious problem for agriculture in coastal regions, wherein salinity is temporal in nature. We studied the effect of salinity, in summer, monsoon and winter seasons, on microbial biomass carbon (MBC) and enzyme activities (EAs) of the salt-affected soils of the coastal region of the Bay of Bengal, Sundarbans, India. The average pH of soils collected from different sites, during different seasons varied from 4.8 to 7.8. The average organic C (OC) and total N (TN) content of the soils ranged between 5.2-14.1 and 0.6-1.4 g kg-1, respectively. The electrical conductivity of the saturation extract (ECe) of soils, averaged over season, varied from 2.2 to 16.3 dSm-1. The ECe of the soils increased five fold during the summer season (13.8 dSm-1) than the monsoon season (2.7 dSm-1). The major cation and anion detected were Na+ and Cl-, respectively. Seasonality exerted considerable effects on MBC and soil EAs, with the lowest values recorded during the summer season. The activities of β-glucosidase, urease, acid phosphatase and alkaline phosphatase were similar during the winter and monsoon season. The dehydrogenase activity of soils was higher in monsoon than in winter. Average MBC, dehydrogenase, β-glucosidase, urease, acid phosphatase and alkaline phosphatase activities of the saline soils ranged from 125 to 346 mg kg-1 oven dry soil, 6-9.9 mg triphenyl formazan (TPF) kg-1 oven dry soil h-1, 18-53 mg p-nitro phenol (PNP) kg-1 oven dry soil h-1, 38-86 mg urea hydrolyzed kg-1 oven dry soil h-1, 213-584 mg PNP kg-1 oven dry soil h-1 and 176-362 mg PNP g-1 oven dry soil h-1, respectively. The same for the non-saline soils were 274-446 mg kg-1 oven dry soil, 8.8-14.4 mg TPF kg-1 oven dry soil h-1, 41-80 mg PNP kg-1 oven dry soil h-1, 89-134 mg urea hydrolyzed kg-1 oven dry soil h-1, 219-287 mg PNP kg-1 oven dry soil h-1 and 407-417 mg PNP kg-1 oven dry soil h-1, respectively. About 48%, 82%, 48%, 63%, 40% and 48% variation in MBC, dehydrogenase activity, β-glucosidase activity, urease activity, acid phosphatase activity and alkaline phosphatase activity, respectively, could be explained by the variation in ECe of saline soils. Suppression of EAs of the coastal soils during summer due to salinity rise is of immense agronomic significance and needs suitable interventions for sustainable crop production. © 2007 Elsevier Ltd. All rights reserved.

Soil Biology and Biochemistry

Enzyme activities and microbial biomass in coastal soils of India

The extent of microbial diversity in nature is still largely unknown, suggesting that there might be many more useful products yet to be identified from soil microorganisms. This insight provides the scientific foundation for a renewed interest in examining soil microorganisms for novel commercially important products. This has led us to access the metabolic potential of soil microorganisms via cultivation strategy. Keeping this in mind, we have performed a culture-dependent survey of important soil bacterial community diversity in East Calcutta Wetland area (Dhapa Landfill Area). We describe isolation of 38 strains, their phenotypic and biochemical characterization, and finally molecular identification by direct sequencing of polymerase chain reaction (PCR)-amplified 16S rRNA gene products. We have isolated and identified strains able to fix nitrogen, produce extracellular enzymes like protease, cellulase, xylanase, and amylase, and solubilize inorganic phosphates. Some isolates can synthesize extracellular insecticidal toxins. We find a good correlation between biochemical and phenotypic behavior and the molecular study using 16S rRNA gene of the isolates. Furthermore, our findings clearly indicate the composition of cultivable soil bacteria in East Calcutta Wetland Area. © 2007 Springer Science+Business Media, LLC.

Journal	Data powered by TypesetMicrobiological Research
Publisher	Data powered by TypesetELSEVIER GMBH, URBAN & FISCHER VERLAG
ISSN	0944-5013
Open Access	No