Production of a new glycolipid biosurfactant from marine Nocardiopsis lucentensis MSA04 in solid-state cultivation.

Considering the need of potential biosurfactant producers and economic production processes using industrial waste, the present study aims to develop solid-state culture (SSC) of a marine actinobacterium for biosurfactant production. A potential biosurfactant producer Nocardiopsis lucentensis MSA04 was isolated from the marine sponge Dendrilla nigra. Among the substrates screened, wheat bran increased the production significantly (E(24) 25%) followed by oil seed cake and industrial waste such as tannery pretreated sludge, treated molasses (distillery waste) and pretreated molasses. Enhanced biosurfactant production was achieved under SSC conditions using kerosene as carbon source, beef extract as nitrogen source and wheat bran as substrate. The maximum production of biosurfactant by MSA04 occurred at a C/N ratio of 0.5 envisaging that a higher amount of nitrogen source is required by the strain compared to that of the carbon source. The kerosene and beef extract interactively increase the production and a stable production was attained with the influence of both factors independently. A significant interactive influence of secondary control factors such as copper sulfate and inoculum size was validated in response surface methods-based experiments. The surface active compound produced by MSA04 was characterized as glycolipid with a hydrophobic non-polar hydrocarbon chain (nonanoic acid methyl ester) and hydrophilic sugar, 3-acetyl 2,5 dimethyl furan. In conclusion, the strain N. lucentensis MSA04 was a potential source of glycolipid biosurfactant, could be used for the development of bioremediation processes in the marine environment.

Optimization, purification, and characterization of extracellular mesophilic alkaline cellulase from sponge-associated Marinobacter sp. MSI032.

Marinobacter sp. (MSI032) isolated from the marine sponge Dendrilla nigra was optimized for the production of extracellular cellulolytic enzyme (CMCase) by submerged fermentation. Initial experiments showed that the culture medium containing 1% maltose as carbon source and 1% peptone and casein as nitrogen source supported maximal enzyme production at 27 degrees C and at a pH of 9.0. Further optimization carried out showed the maximal enzyme production was supported by the presence of 2% NaCl and 10 mM Zn(2+) ions in the production media. The production of enzyme cellulase occurred at 48 h of incubation which proved the importance of this strain for cellulase production in large scale. Further, the enzyme was purified to 12.5-fold with a 37% yield and a specific activity of 2,548.75 U/mg. The purified enzyme displayed maximum activity at mesophilic temperature (27-35 degrees C) and at a broad pH range with optimal activity at pH 9.0. The purified enzyme was stable even at a higher alkaline pH of 12.0 which is greater than the pH stability that has not been reported in any of the cellulolytic isolates studied so far. Thus, from the present study, it is crucial that, instead of exploring the thermophilic resource that is limited in natural environments, the mesophilic bacteria that occurs commonly in nature can be added up to the database of cellulolytic bacteria. Thus, it is possible that a wide diversity of mesophilic bacteria associated with marine sponges opens up a new doorstep for the degradation of cellulosic waste material for the production of liquid fuels. This is the first report elucidating the prospects of sponge-associated marine bacterium for the production of extracellular alkaline cellulase.

Optimization and production of a biosurfactant from the sponge-associated marine fungus Aspergillus ustus MSF3.

Marine endosymbiotic fungi Aspergillus ustus (MSF3) which produce high yield of biosurfactant was isolated from the marine sponge Fasciospongia cavernosa collected from the peninsular coast of India. Maximum production of biosurfactant was obtained in Sabouraud dextrose broth. The optimized bioprocess conditions for the maximum production was pH 7.0, temperature 20 degrees C, salt concentration 3%, glucose and yeast extract as carbon source and nitrogen sources respectively. The response surface methodology based analysis of carbon and nitrogen ratio revealed that the carbon source can increase the biosurfactant yield. The biosurfactant produced by MSF3 was partially characterized as glycolipoprotein based on the estimation of macromolecules and TLC analysis. The partially purified biosurfactant showed broad spectrum of antimicrobial activity. The strain MSF3 can be used for the microbially enhanced oil recovery process.