Isolation, Molecular Characterisation of Polyhydroxyalkanoate Producing Novel Bacillus sp., skm7T from a Polluted Pond Water

Bio-plastics are natural biopolymers that are synthesized and catabolised by various organisms and these materials do not cause toxic effects in the host and have certain advantages over petroleum-derived plastics. The current emphasis on sustainability, eco-efficiency and green chemistry has led to intensive search for renewable and environmentally friendly resources. Thus, sustainable development is recognized to be essential for the growth of the economy and industrial productivity. A polyhydroxyalkanoate (PHA) producing Gram-positive, rod-shaped, motile bacterium was isolated from the polluted pond water. Strain SKM7T grew at 15–40ºC and pH 5.0–8.5 and in the presence of 0–1.5% (w/v) NaCl. The strain was catalase-positive and oxidase-positive. Antimicrobial activities were studied. The DNA G+C content was 53 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain is a member of the genus Bacillus and is most closely related to B. aryabhattai B8W22(T) (99.01%), B. megaterium IAM 13418(T) (98.86%), B. flexus IFO 15715(T) (97.80%). The sequence of the 16S rDNA gene of strain SKM-7 was determined as 1554 bp and deposited in the EMBL under accession no. LM655314. The major isoprenoid quinine was MK-7 and an unidentified glycolipid was identified. The major fatty acid are dominated by saturated iso and anteiso (anteisoC14:0, iso-C15:0, anteisoC15:0, anteisoC16::0). The phenotypic and genotypic properties clearly indicate that strain represents a novel species of the genus Bacillus. The strain produced PHA in mineral medium consisting of glucose and nitrogenous substances. The type strain is SKM7T (=KCTC 33686T).