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Bacillus species are ubiquitous and diverse both in the terrestrial and marine ecosystems. In this investigation, predominant Bacillus species from sea water of three different sites of Orissa Coast were isolated and identified. In total, 16 Bacillus species were identified using morpho-physiological and biochemical characterisation. These identified bacterial strains include B. fastidiosus (CMB1), B. alvei (CMB2), B. coagulans (CMB3), B. marinus (CMB5), B. mycoides (CMB8), B. coagulans (PMB1), B. circulans (PMB2), B. cereus (PMB3), B. subtilis (PMB4), B. alcalophilus (GMB1), B. licheniformics (GMB2), B. polymyxa (GMB3) and B. pumilus (GMB4). The isolates CMB4, CMB6 and CMB7 were identified only up to genus level. These isolates were further screened for their salt tolerance and growth under varied temperature and pH conditions. Ability of these strains to produce extracellular enzymes such as protease, amylase, lipase, gelatinase, casein hydrolase, lecithinase, chitinase and pectinase were also screened and found that most of the Bacillus spp. possess extracellular enzymes.

In vitro study of antibacterial activity of organic solvent extracts of three marine macroalgae viz., Chaetomorpha linum (Mell) Kuetzing, Enteromorpha compressa (L) Greville and Polysiphonia subtilissima Mont. showed specific activity in inhibiting the growth of three Gram-negative bacteria (Shigella flexneri, Vibrio cholerae and Escherichia coli) and two Gram positive bacteria (Bacillus subtilis and Bacillus brevis). The results revealed that the chloroform and ethyl acetate extracts were active against most of the pathogens whereas methanol and ethanol extracts were active only against S. flexneri.

Severe yield loss due to various biotic stresses like bacterial blight (BB), gall midge (insect) and Blast (disease) and abiotic stresses like submergence and salinity is a serious constraint to the rice productivity throughout the world. The most effective and reliable method of management of the stresses is the enhancement of host resistance, through an economical and environmentally friendly approach. Through the application of marker assisted selection (MAS) technique, the present study reports a successful pyramidization of genes/QTLs to confer resistance/tolerance to blast (Pi2, Pi9), gall Midge (Gm1, Gm4), submergence (Sub1) and salinity (Saltol) in a released rice variety CRMAS2621-7-1 as Improved Lalat which had already incorporated with three BB resistance genes xa5, xa13 and Xa21 to supplement the Xa4 gene present in Improved Lalat. The molecular analysis revealed clear polymorphism between the donor and recipient parents for all the markers that are tagged to the target traits. The conventional backcross breeding approach was followed till BC3F1 generation and starting from BC3F1 onwards, marker assisted selection was employed at each step to monitor the transfer of the target alleles with molecular markers. The different BC3F1s having the target genes/QTLs were inter crossed to generate hybrids with all ten stress resistance/tolerance genes/QTLs into a single plant/line. Homozygous Provisional plants for resistance/tolerance genes in different combinations were recovered. The BC3F3 lines were characterized for their agronomic and quality traits and promising progeny lines were selected. The SSR based background selection was done. Most of the gene pyramid lines showed a high degree of similarity to the recurrent parent for both morphological, grain quality traits and in SSR based background selection. Out of all the gene pyramids tested, two lines had all the ten resistance/tolerance genes and showed adequate levels of resistance/tolerance against the five target stresses. The study demonstrates the potential of MAS for stacking of several genes into a single line with a high degree of parental genome recovery. [ABSTRACT FROM AUTHOR]

Fish epidermal mucus contains innate immune components, secreted by globlet cells that provide the primary defence against different pathogenic microbes and act as a barrier between fish and its immediate niche. The major function of mucus includes entrapment and sloughing of microbes. The mucus also contains many factors such as antimicrobial peptides (AMPs), lysozymes, lectins, proteases, etc that provide innate immunity. The AMPs secreted by epidermal mucus cells displayed antimicrobial activity against a variety of pathogens. Besides, mucosal lysozyme was found to produce significant bacteriolytic action whereas different proteases found in skin mucus of fish can kill the pathogens by cleaving its protein or by activating immunological mechanisms. Lectins are also mucosal agglutinins that play a diverse role in innate immunity like opsonization, activation of complement, etc. Epidermal mucus in fish thus provides an innate and fast acting protection which is non-specific and is found to be relatively temperature independent. The aim of the present review is to provide a broad overview of the different components of epidermal mucus including AMPs, proteases, lysozymes as well as their mode of action on pathogens.

Phosphorus is an essential element for all life forms. Phosphate solubilizing bacteria are capable of converting phosphate into a bioavailable form through solubilization and mineralization processes. Hence in the present study a phosphate solubilizing bacterium, PSB-37, was isolated from mangrove soil of the Mahanadi river delta using NBRIP-agar and NBRIP-BPB broth containing tricalcium phosphate as the phosphate source. Based on phenotypic and molecular characterization, the strain was identified as Serratia sp. The maximum phosphate solubilizing activity of the strain was determined to be 44.84 μg/ml, accompanied by a decrease in pH of the growth medium from 7.0 to 3.15. During phosphate solubilization, various organic acids, such as malic acid (237 mg/l), lactic acid (599.5 mg/l) and acetic acid (5.0 mg/l) were also detected in the broth culture through HPLC analysis. Acid phosphatase activity was determined by performing p-nitrophenyl phosphate assay (pNPP) of the bacterial broth culture. Optimum acid phosphatase activity was observed at 48 h of incubation (76.808 U/ml), temperature of 45 °C (77.87 U/ml), an agitation rate of 100 rpm (80.40 U/ml), pH 5.0 (80.66 U/ml) and with glucose as a original carbon source (80.6 U/ml) and ammonium sulphate as a original nitrogen source (80.92 U/ml). Characterization of the partially purified acid phosphatase showed maximum activity at pH 5.0 (85.6 U/ml), temperature of 45 °C (97.87 U/ml) and substrate concentration of 2.5 mg/ml (92.7 U/ml). Hence the present phosphate solubilizing and acid phosphatase production activity of the bacterium may have probable use for future industrial, agricultural and biotechnological application.

Cellulose is an abundant natural biopolymer on earth, found as a major constituent of plant cell wall in lignocellulosic form. Unlike other compounds cellulose is not easily soluble in water hence enzymatic conversion of cellulose has become a key technology for biodegradation of lignocellulosic materials. Microorganisms such as aerobic bacteria, fungi, yeast and actinomycetes produce cellulase that degrade cellulose by hydrolysing the β-1, 4-glycosidic linkages of cellulose. In contrast to aerobic bacteria, anaerobic bacteria lack the ability to effectively penetrate into the cellulosic material which leads to the development of complexed cellulase systems called cellulosome. Among the different environments, the sediments of mangrove forests are suitable for exploring cellulose degrading microorganisms because of continuous input of cellulosic carbon in the form of litter which then acts as a substrate for decomposition by microbe. Understanding the importance of cellulase, the present article overviews the diversity of cellulolytic microbes from different mangrove environments around the world. The molecular mechanism related to cellulase gene regulation, expression and various biotechnological application of cellulase is also discussed.

Objective: To investigate the in vitro antioxidant and antimicrobial activities along with phytochemical screening of organic and aqueous extracts of leaf and stem of Suaeda maritima (Dumort), a mangrove associate from Bhitarkanika of Odisha, India., Methods: Antioxidant activity of the crude extracts was evaluated in terms of total antioxidant capacity, total phenol content, ascorbic acid content, DPPH radical scavenging, metal chelating, nitric oxide scavenging, and reducing power etc. The antimicrobial activity of the plant was determined by agar well diffusion method along with MIC and MBC carried out by microdilution techniques against 10 gram positive and gram negative human pathogenic bacteria. The qualitative and quantative phytochemical screening were carried out by standard biochemical assays., Results: Out of the seven antioxidant bioassays, both the leaf and stem extracts were found to posses strong antioxidant properties of 70 % to 92 % for phenol, total antioxidant capacity, DPPH free radical scavenging activity and fairly good ascorbic acid content, metal chelating (1.33 %-22.55 %), reducing power (0.01-0.12) and nitric oxide scavenging (0.84 %-66.99 %) activities. Out of the four extracts evaluated for antimicrobial activity, two leaf extracts such as acetone and ethanol showed promising activity against four pathogenic bacteria and one stem methanol extracts against one pathogenic bacteria when compared with amoxcycillin as standard. The MIC and MBC values of the antimicrobial extracts ranged between 2.5 to 5.0 mg/mL. Screening of phytochemicals showed presence of carbohydrates, protein, tannins, alkaloids and flavonoids in comparatively higher amount than other phytochemicals tested., Conclusions: The present study reveals the presence of potential antioxidants and antimicrobial properties in the plant extract which could be exploited for pharmaceutical application., (Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)