The cold adapted microorganisms, psychrophiles/psychrotolerants, go through several modifications at cellular and biochemical levels to alleviate the influence of low temperature stress conditions. The low temperature environments depend on these cold adapted microorganisms for various ecological processes. The ability of the microorganisms to function in cold environments depends on the strategies directly associated with cell metabolism, physicochemical constrains, and stress factors. Pseudomonas is one among such group of microorganisms which is predominant in cold environments with a wide range of ecological and biotechnological applications. Bioformulations of Pseudomonas spp., possessing plant growth promotion and biocontrol abilities for application under low temperature environments, are well documented. Further, recent advances in high throughput sequencing provide essential information regarding the prevalence of Pseudomonas in rhizospheres and their role in plant health. Cold adapted species of Pseudomonas are also getting recognition for their potential in biodegradation and bioremediation of environmental contaminants. Production of enzymes and bioactive compounds (primarily as an adaptation mechanism) gives way to their applications in various industries. Exopolysaccharides and various biotechnologically important enzymes, produced by cold adapted species of Pseudomonas, are making their way in food, textiles, and pharmaceuticals. The present review, therefore, aims to summarize the functional versatility of Pseudomonas with particular reference to its peculiarities along with the ecological and biotechnological applications.

The present study aims to investigate the effect of extraction method on the recovery of flavonoid glycosides, antimicrobials and antioxidants from Ginkgo leaves collected from six different locations in Uttarakhand, Indian Himalaya. Four extraction methods, namely maceration, reflux, shaker and soxhlet were considered, where reflux extracts showed higher antimicrobial antioxidant activity and higher content of flavonoid glycosides. The reference standards of Ginkgo flavonoid glycosides (quercetin, kaempferol and isorhamnetin) and crude extracts were tested for their antimicrobial activity against gram positive and gram negative bacteria and fungi following disc diffusion method and minimum inhibitory concentration (MIC). All the test microorganisms were observed to be inhibited significantly by Ginkgo flavonoids in plate based assays. Correlation coefficients exhibited the extent of contribution of flavonoid glycosides in antimicrobial activity and confirmed the reflux method as a potential method for extraction. Moreover, antioxidant activity as measured by DPPH assay was also found to be higher in reflux method. Significant variation (p < 0.05) in the flavonoid glycosides among the locations was also observed and sample collected from GB6 location was found to be the best for quercetin and isorhamnetin, while GB5 for kaempferol. Significant correlation (r < 0.05, r < 0.001) was obtained while developing the relationship between total flavonoid glycosides and antimicrobials. The present study, thus suggests the reflux method of extraction to be the best for maximum recovery of flavonoid glycosides with higher antioxidant and antimicrobial activities from Ginkgo extract.