Search

The co-production of industrially relevant biopolymers/biomolecules from microbes is of biotechnological importance. Herein, a unique bacterium, Iodobacter sp. PCH 194 from the kettle lake at Sach Pass in western Indian Himalaya was identified. It co-produces biopolymer polyhydroxyalkanoates (PHA) and biomolecule (violacein pigment). Statistical optimization yielded dual products in the medium augmented with glucose (4.0% w/v) and tryptone (0.5% w/v) as carbon and nitrogen sources, respectively. The purified PHA was polyhydroxybutyrate (PHB), and pigment constitutes of violacein (50-60%) and deoxyviolacein (40-50%). A bench-scale bioprocess in 22.0 L fermentor with 20% dissolved O 2 supply produced PHB (11.0 ± 1.0 g/L, 58% of dry cell mass) and violacein pigment (1.5 ± 0.08 g/L). PHB obtained was used for the preparation of bioplastic film. Violacein pigment experimentally validated for anticancerous and antimicrobial activities. In summary, a commercially implied bioprocess developed for the co-production of PHB and violacein pigment using the Himalayan bacterium., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Extreme niches are offered with unusual physiochemical conditions that impose stress to the life-forms including microbial communities. Microbes have evolved unique physiology and genetics to interact dynamically with extreme environments for their adaptation and survival. Amongst the several adaptive features of microbes in stressed conditions, polyhydroxyalkanoates synthesis is a crucial strategy of many bacteria and archaea to reserve carbon and energy inside the cell. Apart from the relevance of PHA to microbial world, these intracellular polyesters are seen as essential biological macromolecules for the bio-material industry owing to their plastic-like properties, biodegradable and eco-friendly nature. Recently, much attention has been attracted by the microbes of extreme habitats for a new source of industrially suited PHA producers and novel PHA with unique properties. Therefore, the current review is focused on the critical evaluation of microbes from extreme niches for PHA production and opportunities for the development of commercially feasible PHA bioprocess., Competing Interests: Declaration of Competing Interest The authors declared no conflict of interest., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Himalaya hosts a unique environment for microbial ecology. The present study aimed to explore the bioplastic producing bacterial communities along altitude gradient of Pangi-Chamba trans-Himalayan region. A total of 411 bacteria were isolated and 70 characterized at the molecular level for potential polyhydroxyalkanoates (PHA) producers. The most abundant phylum for PHA synthesis was Proteobacteria (73%), followed by Actinobacteria (11%), Firmicutes (10%) and Bacteroidetes (6%). However, at the genus level, Pseudomonas and Janthinobacterium were dominantly reported. Also, the ability to synthesize PHA was reported for the first time for few genera such as Collimonas, Pseudarthrobacter and Paenarthrobacter. Phylogenetic analysis of partial 16S rDNA and phaC genes revealed conservation in phaC and possibility of horizontal gene transfer among distant taxa. Furthermore, GC-MS also confirmed the ability of potential bacterial isolates to synthesize PHA. In fact, we found that PHA-positive bacteria are dominant in the high altitude of Himalaya, suggesting the vital role of PHA in bacterial adaptation and survival. Together, these findings had revealed the rich bacterial diversity and genetic machinery for PHA synthesis which does have potential for further utilization in the commercial applications.

Himalayan niches provide unprecedented opportunities for finding novel microbes of commercial importance. The present study investigated the genome sequence of Glaciimonas sp. PCH181 isolated from the glacial stream of Indian trans-Himalaya. The draft genome sequence has six contigs with 5.3 Mb size, 51.1% G + C content, and possesses 4876 genes. Phylogenomic analysis revealed PCH181 as a putative novel bacterium in the genus Glaciimonas. Genomic insight showed Glaciimonas sp. PCH181 enriched with genes for diverse physiology, cold/stress adaptation, and industrial potential. The presence of genes for CO 2 fixation and hydrogen metabolism suggested for chemolithoautotrophy. However, genes for sugars and organic acids usage showed heterotrophy and validated by physiological experiments. Genes for the metabolism of phenol (up to 500 ppm) and biosynthesis of polyhydroxyalkanoate (25% of dry cell mass) were also verified. Collectively, we present the first whole genome sequencing in the genus Glaciimonas , a taxonomically, physiologically, and industrially noteworthy bacterium. • First genome sequencing report in the genus Glaciimonas isolated from Himalayan glacier. • Genomic insights revealed Glaciimonas sp. PCH181 taxonomically, physiologically, and industrially noteworthy bacterium. • Genes encoding enzymes for phenol degradation and polyhydroxyalkanoates biosynthesis were identified in the genome. • Glaciimonas sp. PCH181 metabolizes diverse carbon sources, synthesize polyhydroxybutyrate and degrade phenol. [ABSTRACT FROM AUTHOR]