Bioprospecting and characterization of laccase producing bacteria from paddy fields of Himachal Pradesh

Laccase is a copper containing polyphenol oxidase that acts on a wide range of substrates, and thus used in several industrial and biotechnological applications. This enzyme is found in many plant species and is widely distributed in fungi and mostly fungal laccases are used in biotechnological applications. In contrast, little is known about bacterial laccases, although bioinformatic analysis revealed high diversity of bacterial genes for laccase like enzyme and suggests that the enzymes are widespread in bacteria. Since bacterial genetic tools and biotechnological processes are well established, developing bacterial laccases would be significantly important. Thus in the present study, significant high diversity of laccase producing bacteria from rhizosphere of rice plants from paddy fields of Himachal Pradesh was assessed. A total of 375 bacteria were isolated using Tryptone Yeast agar medium containing 5 mM guaiacol as substrate and 40 mg/L CuSO4. Secondary screening for laccase activity based on their ability to oxidise tannic acid and laccase specific substrate dimethoxyphenol led to selection of 51 bacterial isolates. On the basis of morphological and biochemical characterization and laccase activity, nine bacterial isolates exhibiting maximum laccase activity were selected and molecular characterization was carried out using 16S rRNA gene technology. In silico analysis of 16S rRNA sequences identified these bacterial isolates as Pseudomonas and Lysinibacillus sp.

Partial molecular characterization of some kiwi fruit cultivars by RAPD markers.

Molecular variability among seven cultivars of A. deliciosa var. deliciosa was investigated through RAPD markers. Thirty four decamer primers were screened generating polymorphic patterns of amplified DNA for these cultivars. Twenty one selected primers gave clear and reporducible patterns. A total of 430 bands were produced and 29.37% of them were polymorphic. The patterns distinguished between the cultivars and their analysis established an approach to classification within A. deliciosa var. deliciosa based on RAPD markers. The dendrogram clearly differentiated male from female cultivars. While abbot and allison female cultivars were closely related, bruno and abbot female cultivars showed maximum dissimilarity.