Central University of Kerala

About: Central University of Kerala is a education organization based out in Kāsaragod, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 556 authors who have published 881 publications receiving 7474 citations.

Isolation and characterization of alginate-degrading bacteria Sinomicrobium oceani

Abstract: This research work is focused on identifying alginate-degrading bacteria from various marine as well as alginate industrial substrates using basal salt medium with alginate as sole source of carbon. In the present study, alginate-degrading colonies formed soft pits on the surface of the medium with clear haloes around them gradually degrading the solid medium into liquid on day 7. The isolate positive for alginolytic activity formed a circular pale yellow zone around the colony. Out of the 23 isolates studied, 11 exclusively isolated from the alginate industrial wastes were chosen for the degradation study. On the basis of bacterial growth, total sugar, reducing sugar and total protein in the culture medium, isolates AAl 01, AAl 02, AAl 03 and AAl 04 were selected of which consortium AAl 02 + AAl 04 was found promising for maximum alginate lyase activity on day 4 of inoculation at 28 °C with pH 7.5. Batch culture studies showed that fresh biomass of Sargassum wightii produced 37.88 ± 1.37 % of reducing sugar by direct saccharification using bacterial consortium, whereas by acid pretreatment + bacterial consortium, the yield was 62.69 ± 2.90 %. In the case of pigment-phycocolloid spent, 82.41 ± 4.50 % of reducing sugar was released using bacterial consortium, whereas by mild acid pretreatment + bacterial consortium, 86.68 ± 7.11 % was achieved. Results of morphology, biochemical tests and 16S rRNA sequence confirmed the two promising isolates as Sinomicrobium oceani (AAl 02 and AAl 04) belonging to Flavobacteriaceae. Seaweed biomass degradation using biological methods is non-toxic and considered environmentally safe.

Evidence for independent domestication of sheep mtDNA lineage A in India and introduction of lineage B through Arabian sea route.

Abstract: India ranks the second in the world in terms of its sheep population with approximately 74.26 million represented by 44 well-described breeds in addition to several non-descript populations. Genetic diversity and phylogeography of Indian sheep breeds remain poorly understood, particularly for south Indian breeds. To have a comprehensive view of the domestication history of Indian sheep, we sequenced the mitochondrial DNA (mtDNA) control region (D-loop) and cytochrome b gene (CYTB) of 16 Indian domestic sheep breeds, most of them (13) from the south India. We analysed these sequences along with published data of domestic and wild sheep from different countries, including India. The haplotype diversity was relatively high in Indian sheep, which were classified into the three known mtDNA lineages, namely A, B and C. Lineage A was predominant among Indian sheep whereas lineages B and C were observed at low frequencies but C was restricted to the breeds of north and east India. The median joining network showed five major expanding haplogroups of lineage A (A1–A5). Out of which, A2, A4 and A5 were more frequent in Indian sheep in contrast to breeds from other parts of the world. Among the 27 Indian sheep breeds analysed, Mandya and Sonadi breeds were significantly different from other Indian breeds in the MDS analyses. This was explained by a very high contribution of lineage B into these two breeds. The Approximate Bayesian Computation (ABC) provided evidence for the domestication of lineage A sheep in the Indian subcontinent. Contrary to the current knowledge, we also found strong support for the introduction of lineage B into Indian subcontinent through sea route rather than from the Mongolian Plateau. The neighbour-joining tree of domestic and wild sheep revealed the close genetic relationship of Indian domestic sheep with Pakistani wild sheep O. vignei blanfordi. Based on our analyses and archaeological evidences, we suggest the Indian subcontinent as one of the domestication centres of the lineage A sheep, while lineage B sheep might have arrived into India from elsewhere via Arabian sea route. To the best of our knowledge, this is the first comprehensive study on Indian sheep where we have analysed more than 740 animals belonging to 27 sheep breeds raised in various regions of India. Our study provides insight into the understanding of the origin and migratory history of Indian sheep.