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 (E24 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.