Extraction and bioactive profile of the compounds produced by Rhodococcus sp. VLD-10
Biotech
Extraction and bioactive profile of the compounds produced by Rhodococcus sp. VLD-10
Bokka Yellamanda 0 1 2
Muvva Vijayalakshmi 0 1 2
Alapati Kavitha 0 1 2
Dorigondla Kumar Reddy 0 1 2
Yenamandra Venkateswarlu 0 1 2
0 Division of Natural Products, Indian Institute of Chemical Technology , Hyderabad 500 007 , India
1 Department of Biochemistry, Indian Institute of Science , Bangalore 560 012 , India
2 Department of Botany and Microbiology, Acharya Nagarjuna University , Guntur 522 510 , India
A potent actinobacterial strain isolated from the marine samples of Bheemunipatnam beach, Visakhapatnam, India, was identified as Rhodococcus sp. VLD-10 using the conventional and genomic (16S rRNA) approaches. Bioactive compounds responsible for the antimicrobial activity of the strain were elucidated by cultivating the strain VLD-10 in a modified yeast extract-malt extractlactose broth followed by subsequent chromatographic and spectroscopic analyses. Extraction, purification, and structural confirmation of five compounds, viz., benzoic acid, 2-nitrobenzaldehyde, 4-chlorobenzaldehyde, nonadeconoic acid, and 3-isopropylhexahydro-1H-pyrido[1,2-a] pyrazine-1,4(6H)-dione, from Rhodococcus sp. VLD-10 were fruitfully described. The bioactivity of the compounds isolated from the strain VLD-10 against Gram-positive as well as Gram-negative bacteria, yeast, and molds was tested and their minimum inhibition concentration was reported. Antibacterial activity of 3-isopropylhexahydro1H-pyrido[1,2-a] pyrazine-1,4(6H)-dione is more prominent against Bacillus subtilis, B. cereus, B. megaterium, Corynebacterium diphtheriae, and Escherichia coli, whereas its antifungal spectrum showed less potency against yeast and fungi. This is the first report on the natural occurrence and bioactivity of 3-isopropylhexahydro1H-pyrido[1,2-a] pyrazine-1,4(6H)-dione from Rhodococcus sp. VLD-10.
Actinobacteria Rhodococcus Bioactive compounds 3-Isopropylhexahydro-1H-pyrido[1; 2-a] pyrazine-1; 4(6H)-dione
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& Muvva Vijayalakshmi
Microorganisms are capable of carrying out a tremendous
variety of reactions and can adapt to a range of
environments allowing them to be transplanted from nature to the
laboratory where they can be grown on inexpensive carbon
and nitrogen sources to produce valuable compounds
(Narayana and Vijayalakshmi 2008; Manivasagan et al.
2013). Because of their biological activity, secondary
metabolites of microbial origin are extremely important to
our health and nutrition, and have a tremendous economic
importance. The screening of microbial natural products
continues to represent an important route to the discovery
of novel chemicals, for development of new therapeutic
agents and for evaluation of the potential of lesser-known
or new bacterial taxa (Kurtboke and Wildman 1998;
Ramesh and William 2012). Natural products or their
derivatives remain the most significant source of novel
medicines (Newman et al. 2003; Fenical 2006; Lam 2007;
Manivasagan et al. 2013). Among the potential sources of
natural products, bacteria are proven to be a predominantly
prolific resource with a surprisingly small group of taxa
accounting for the vast majority of compounds discovered
(Keller and Zengler 2004). Among them, bacteria
belonging to the order Actinomycetales (commonly called
actinobacteria) are distributed ubiquitous in nature and
account for more than 50% of the compounds reported in
the Dictionary of Natural Products.
In world’s 70% water ecosystem, Indian marine
environment is believed to have rich microbial diversity.
However, the wealth of indigenous marine microflora has
not been fully explored. Most of the studies on marine
microorganisms have been limited to isolation,
identification, and maintenance of these organisms on different
culture media. Their biotechnological potentials are yet to
be fully explored (Sivakumar et al. 2007; Manivasagan
et al. 2013). East Coast of India is reported to be a major
source of actinobacteria (Sambamurthy and Ellaiah 1974;
Balagurunathan 1992; Dhanasekaran et al. 2005;
Vijayakumar et al. 2007). Therefore, there is tremendous
scope to identify new or rare marine microorganisms from
this region and also to discover novel microbial metabolites
with diverse biological activities (Dhanasekaran et al.
2005; Ramesh and Mathivanan 2009; Ramesh and William
2012). The recent discovery of novel secondary
metabolites from taxonomically unique populations of marine
actinobacteria suggested that these bacteria add an
important new dimension to microbial natural product research.
Continued efforts to characterize marine actinobacterial
diversity and how adaptations to the marine environment
affect secondary metabolite production will create a better
understanding of the potential utility of these bacteria as a
source of useful products for biotechnology (Jensen et al.
2015). These findings will hopefully encourage additional
studies addressing the ecological roles of actinobacteria in
the marine envir (...truncated)