Whey, the main by-product obtained from the manufacture of cheese, which contains a very high organic load (mainly due to the lactose content), is not easily degradable and creates concern over environmental issues. Hydrolysis of lactose present in whey and conversion of whey lactose into valuable products such as bioethanol, sweet syrup, and animal feed offers the possibility of whey bioremediation. The increasing need for bioremediation in the dairy industry has compelled researchers to search for a novel source of β-galactosidase with diverse properties. In the present study, the bacterium Paracoccus marcusii KGP producing β-galactosidase was subjected to morphological, biochemical, and probiotic characterisation. The bacterial isolate was found to be non-pathogenic and resistant to low pH (3 and 4), bile salts (0.2%), salt (10%), pepsin (at pH 3), and pancreatin (at pH 8). Further characterisation revealed that the bacteria have a good auto-aggregation ability (40% at 24 h), higher hydrophobicity (chloroform-60%, xylene-50%, and ethyl acetate-40%) and a broad spectrum of antibiotic susceptibility. The highest growth of P. marcusii KGP was achieved at pH 7 and 28 °C, and the yeast extract, galactose, and MgSO4 were the best for the growth of the bacterial cells. The bacterium KGP was able to utilise whey as a substrate for its growth with good β-galactosidase production potential. Furthermore, the β-galactosidase extracted from the isolate KGP could hydrolyse 47% whey lactose efficiently at 50 °C. The study thus reveals the potential application of β-galactosidase from P. marcusii KGP in whey bioremediation.

• MeSH
• biodegradace MeSH
• mlékárenství MeSH
• Paracoccus * metabolismus   MeSH
• probiotika * metabolismus   MeSH
• průmyslový odpad * MeSH
• syrovátka * mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• průmyslový odpad * MeSH

A new β-galactosidase-producing bacterium KGP, isolated from the Bay of Bengal, was identified as Paracoccus marcusii through morphology, biochemistry and 16S rRNA sequencing. This study is the first report on the production of β-galactosidase from P. marcusii. The medium components for the high yield of β-galactosidase were optimised using response surface methodology (RSM). A set of 17 experiments consisting of three independent variables, viz. yeast extract, galactose and MgSO4, was employed. A second-order polynomial equation was used for the analysis of the response, and the optimum β-galactosidase yield was achieved using 12.5 g/L yeast extract, 12.5 g/L galactose and 12.5 mmol/L MgSO4. The predicted quadratic model was inferred to be significant from the F-value, P value and the lack of fit value. Optimisation of the media components resulted in a ninefold increase (560 Miller units) in β-galactosidase production. Furthermore, the hydrolysis and transgalactosylation efficiency of the crude β-galactosidase was assessed and the results showed that the lactose was successfully hydrolysed and transgalactosylated at an optimum temperature of 40 °C and 50 °C, respectively. Considering the overall yield and productivity, P. marcusii can be considered a candidate for the industrial production of β-galactosidase. This study provides an essential basis for the future production and use of the alkali-tolerant β-galactosidase from P. marcusii KGP.

• MeSH
• beta-galaktosidasa metabolismus   MeSH
• bioreaktory MeSH
• fylogeneze MeSH
• galaktosa metabolismus   MeSH
• hydrolýza MeSH
• koncentrace vodíkových iontů MeSH
• laktosa metabolismus   MeSH
• oligosacharidy biosyntéza   MeSH
• Paracoccus klasifikace   genetika   izolace a purifikace   metabolismus   MeSH
• RNA ribozomální 16S genetika   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• beta-galaktosidasa MeSH
• galaktosa MeSH
• laktosa MeSH
• oligosacharidy MeSH
• RNA ribozomální 16S MeSH