10 research outputs found
Isolation and characterisation of plant growth-promoting bacterial and fungal endophytes from Himalayan Yew (Taxus wallichiana) - an economically imperative pant of Himalayas
It is a known fact that the bacterial and fungal endophytes inhabit the plant tissues besides aiding in the better
growth and health of the plants. The bark and leaves of Taxus wallichiana have drawn a lot of interest in recent years
since they are the richest source of taxol, an anticancer drug. As it is a slow-growing tree that can only be regenerated
via vegetative propagation, it has been classified as a critical rare species due to its extensive collection for medicinal
and other purposes. Nonetheless, the use of endophytes as plant growth promoters is gaining much importance among
environmentalists and agronomists because of their imperative role in crop production. Even then, there is hardly any
information available regarding the growth-promoting endophytes isolated from bark and leaves associated with T.
wallichiana commonly known as Himalayan Yew. Therefore, the present study was undertaken to isolate fungal and
bacterial endophytes from T. wallichiana and to classify the growth-promoting properties of these endophytes. In total,
seven fungal and ten bacterial endophytes were obtained from different parts of T. wallichiana. All of the isolated fungal
and bacterial endophytes produced indole acetic acid while most of them also produced ammonia. Besides, the fungal
and bacterial endophytes were also screened for antimicrobial and various enzymatic activities. Based on the above
results, the two fungal endophytes were selected for their possible ability to promote seed growth. The results showed
that the fungal endophytes isolated from T. wallichiana played an active role in increasing growth in other plant species
and therefore, can be used as potential plant growth promoters
Evaluation of cellobiose dehydrogenase and laccase containing culture fluids of Termitomyces sp. OE147 for degradation of Reactive blue 21
This study evaluates culture filtrate, rich in cellobiose dehydrogenase and laccases, of Termitomyces sp. OE 147, in decolouration and degradation of Reactive blue (RB) 21. About 35% decolouration was achieved at low volumes of the culture supernatant without addition of external redox mediators. An optimized dye to culture fluid ratio (75 ppm: 0.1 ml) at a pH of 4–5 resulted in removal of colour by 60%. The degradation products of RB21 were analysed by Electron Spray Ionization-Mass Spectrometry and several small molecules (of m/z 106–199) were detected. These were concluded to be o-Xylene, 2,3-Dihydro-1H-isoindole, Isoindole-1,3-dione, 2,Benzenesulfonyl-ethanol, (4-Hydroxy-phenyl)-sulfamic acid, 2,3-Dihydro-1H-isoindole-5-sulfonic acid and proposed to result from joint action of cellobiose dehydrogenase, laccase, peroxidases and unidentified oxidoreductases present in the culture fluids. Based on the products formed and the known reactions of these enzymes, a degradation pathway was proposed for RB21. The culture fluid was also effective in decolouration (by about 50%) and detoxification (by ∼25%) of the combined effluent collected from a local mill indicating a treatment process that bypasses use of H2O2 and toxic mediators
A cold-active esterase of Streptomyces coelicolor A3(2): from genome sequence to enzyme activity
The genome sequence of Streptomyces coelicolor
A3(2) contains 51 putative lipase and esterase genes
mostly of unknown function. The gene estB (locus SCO
6966) was expressed as a His-tagged protein in E. coli.
Esterase B was active at low temperatures exerting its maximum activity at 30°C and retaining more than 25% of its
activity at 4°C. The optimum pH was 8–8.5. The enzyme
was active against short synthetic p-nitrophenylesters
(C2–C10) with maximum activity towards the acetate ester
(C2). The esterase was tested on 13 series of racemic esters
of potential interest for the synthesis of chiral pharmaceutical compounds. 4 of the series were substrates and a modestdegree of enantioselectivity was observed (enantiomeric ratios of 1.1–1.9)
Molecular cloning of carboxylesterase gene and biochemical characterization of encoded protein from Bacillus subtilis (RRL BB1)
An isolated strain of Bacillus subtilis identified by 16S rDNA sequence analysis produces an enantioselective ester hydrolase.Whole cells of B. subtilis (RRL BB1) and enzyme derived from it was capable of enantioselective hydrolysis of several racemates including drug intermediates with moderate to high enantioselectivity as already reported by us. In this communication, we describe cloning of the gene encoding the enantioselective esterase designated as estBB1. The primary structure of the enzyme determined from the nucleotide sequence indicated that esterase estBB1 has Mw ∼52 kDa and pI ∼5.2 and belongs to the family of type B carboxylesterases with 50–60% similarity at amino acid level. Alignment studies of sequences of the estBB1 and Pnb
esterase 56C8 from B. subtilis showed that estBB1 has an �/� hydrolase fold with catalytic triad formed by Ser190, Glu305 and His394 at active site and Ser190 is located in the conserved motif –G–X–S–X–G–
Molecular cloning of enantioselective ester hydrolase fromBacillus pumilusDBRL-191
A gene from Bacillus pumilus expressed under its native promoter was cloned in Escherichia coli. Recombinant B. pumilus esterase(BPE) affects the kinetic resolution of racemic mixtures such as unsubstituted and substituted 1-(phenyl)ethanols (E � 33–103), ethyl 3-hydroxy-3-phenylpropanoate (E � 45–71), trans-4-fluorophenyl-3-hydroxymethyl-N-methylpiperidine (E � 10–13) and ethyl 2-
hydroxy-4-phenylbutyrate (E � 7). The enzyme is composed of a 34-amino acid signal peptide and a 181-amino acid mature protein corresponding to a molecular weight of �19.2 kD and pI � 9.4. 3-D the structural model of the enzyme built by homology modelling using the atomic coordinates from the crystal structure of B. subtilis lipase (LipA) showed a compact minimal a/b hydrolase fold
An update of pathogenic variants in ASPM, WDR62, CDK5RAP2, STIL, CENPJ, and CEP135 underlying autosomal recessive primary microcephaly in 32 consanguineous families from Pakistan
Background: Primary microcephaly (MCPH) is a congenital neurodevelopmental disorder manifesting as small brain and intellectual disability. It underlies isolated reduction of the cerebral cortex that is reminiscent of early hominids which makes it suitable model disease to study the hominin-specific volumetric expansion of brain. Mutations in 25 genes have been reported to cause this disorder. Although majority of these genes were discovered in the Pakistani population, still a significant proportion of these families remains uninvestigated. Methods: We studied a cohort of 32 MCPH families from different regions of Pakistan. For disease gene identification, genome-wide linkage analysis, Sanger sequencing, gene panel, and whole-exome sequencing were performed. Results: By employing these techniques individually or in combination, we were able to discern relevant disease-causing DNA variants. Collectively, 15 novel mutations were observed in five different MCPH genes; ASPM (10), WDR62 (1), CDK5RAP2 (1), STIL (2), and CEP135 (1). In addition, 16 known mutations were also verified. We reviewed the literature and documented the published mutations in six MCPH genes. Intriguingly, our cohort also revealed a recurrent mutation, c.7782_7783delGA;p.(Lys2595Serfs*6), of ASPM reported worldwide. Drawing from this collective data, we propose two founder mutations, ASPM:c.9557C>G;p. (Ser3186*) and CENPJ:c.18delC;p.(Ser7Profs*2), in the Pakistani population. Conclusions: We discovered novel DNA variants, impairing the function of genes indispensable to build a proper functioning brain. Our study expands the mutational spectra of known MCPH genes and also provides supporting evidence to the pathogenicity of previously reported mutations. These novel DNA variants will be helpful for the clinicians and geneticists for establishing reliable diagnostic strategies for MCPH families