Dataset Information

Screening and production of a potential extracellular fungal laccase from Penicillium chrysogenum: Media optimization by response surface methodology (RSM) and central composite rotatable design (CCRD).

ABSTRACT: This paper describes the isolation of potent extracellular-laccase producing white-rot fungus, identified by 18 s-rRNA as Penicillium-chrysogenum and its medium optimization by central-composite-rotatable-design using RSM. The optimum laccase-activity of 6.0 U ml^-1 was obtained and maximum activity of 7.9 U ml^-1 was achieved by statistical-optimization of the medium at 32 °C for 5 days. The molecular-weight of the laccase was found to be 67 kDa. UV-visible absorption-spectrum analysis shows peak at 600 nm and 325 nm corresponding to the type-I Cu(II) & type-III binuclear Cu(II) pair respectively confirming presence of laccase. The sharp endothermic peak at 150 °C and three-phases of protein denaturation was observed by DSC and TGA analysis for enzyme protein. The FT-IR analysis of laccase shows band at 1405cm^-1, 1656 cm^-1 &3400cm^-1 corresponding to amide-I band, amide-II band and amino-acid group respectively. Results of the study show the enzyme is capable of carrying-out hydrolytic-cleavage of chemical-pollutants from the industrial waste-water for providing sustainable-greener environment.

SUBMITTER: Senthivelan T

PROVIDER: S-EPMC6541886 | biostudies-literature | 2019 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Screening and production of a potential extracellular fungal laccase from Penicillium chrysogenum: Media optimization by response surface methodology (RSM) and central composite rotatable design (CCRD).

Senthivelan T T Kanagaraj J J Panda Rames C RC Narayani T T

Biotechnology reports (Amsterdam, Netherlands) 20190517

This paper describes the isolation of potent extracellular-laccase producing white-rot fungus, identified by 18 s-rRNA as Penicillium-chrysogenum and its medium optimization by central-composite-rotatable-design using RSM. The optimum laccase-activity of 6.0 U ml-1 was obtained and maximum activity of 7.9 U ml-1 was achieved by statistical-optimization of the medium at 32 °C for 5 days. The molecular-weight of the laccase was found to be 67 kDa. UV-visible absorption-spectr ...[more]

PMID: 31193735

Similar Datasets

Project description:BACKGROUND: Penicillium chrysogenum converts isopenicillin N (IPN) into hydrophobic penicillins by means of the peroxisomal IPN acyltransferase (IAT), which is encoded by the penDE gene. In silico analysis of the P. chrysogenum genome revealed the presence of a gene, Pc13g09140, initially described as paralogue of the IAT-encoding penDE gene. We have termed this gene ial because it encodes a protein with high similarity to IAT (IAL for IAT-Like). We have conducted an investigation to characterize the ial gene and to determine the role of the IAL protein in the penicillin biosynthetic pathway. RESULTS: The IAL contains motifs characteristic of the IAT such as the processing site, but lacks the peroxisomal targeting sequence ARL. Null ial mutants and overexpressing strains indicated that IAL lacks acyltransferase (penicillin biosynthetic) and amidohydrolase (6-APA forming) activities in vivo. When the canonical ARL motif (leading to peroxisomal targeting) was added to the C-terminus of the IAL protein (IAL ARL) by site-directed mutagenesis, no penicillin biosynthetic activity was detected. Since the IAT is only active after an accurate self-processing of the preprotein into alpha and beta subunits, self-processing of the IAL was tested in Escherichia coli. Overexpression experiments and SDS-PAGE analysis revealed that IAL is also self-processed in two subunits, but despite the correct processing, the enzyme remained inactive in vitro. CONCLUSION: No activity related to the penicillin biosynthesis was detected for the IAL. Sequence comparison among the P. chrysogenum IAL, the A. nidulans IAL homologue and the IAT, revealed that the lack of enzyme activity seems to be due to an alteration of the essential Ser309 in the thioesterase active site. Homologues of the ial gene have been found in many other ascomycetes, including non-penicillin producers. Our data suggest that like in A. nidulans, the ial and penDE genes might have been formed from a single ancestral gene that became duplicated during evolution, although a separate evolutive origin for the ial and penDE genes, is also discussed.

Project description:BackgroundCephalosporins and penicillins are the most frequently used β-lactam antibiotics for the treatment of human infections worldwide. The main industrial producers of these antibiotics are Acremonium chrysogenum and Penicillium chrysogenum, two taxonomically unrelated fungi. Both were subjects of long-term strain development programs to reach economically relevant antibiotic titers. It is so far unknown, whether equivalent changes in gene expression lead to elevated antibiotic titers in production strains.ResultsUsing the sequence of PcbC, a key enzyme of β-lactam antibiotic biosynthesis, from eighteen different pro- and eukaryotic microorganisms, we have constructed a phylogenetic tree to demonstrate the distant relationship of both fungal producers. To address the question whether both fungi have undergone similar genetic adaptions, we have performed a comparative gene expression analysis of wild-type and production strains. We found that strain improvement is associated with the remodeling of the transcriptional landscape in both fungi. In P. chrysogenum, 748 genes showed differential expression, while 1572 genes from A. chrysogenum are differentially expressed in the industrial strain. Common in both fungi is the upregulation of genes belonging to primary and secondary metabolism, notably those involved in precursor supply for β-lactam production. Other genes not essential for β-lactam production are downregulated with a preference for those responsible for transport processes or biosynthesis of other secondary metabolites. Transcriptional regulation was shown to be an important parameter during strain improvement in different organisms. We therefore investigated deletion strains of the major transcriptional regulator velvet from both production strains. We identified 567 P. chrysogenum and 412 A. chrysogenum Velvet target genes. In both deletion strains, approximately 50% of all secondary metabolite cluster genes are differentially regulated, including β-lactam biosynthesis genes. Most importantly, 35-57% of Velvet target genes are among those that showed differential expression in both improved industrial strains.ConclusionsThe major finding of our comparative transcriptome analysis is that strain improvement programs in two unrelated fungal β-lactam antibiotic producers alter the expression of target genes of Velvet, a global regulator of secondary metabolism. From these results, we conclude that regulatory alterations are crucial contributing factors for improved β-lactam antibiotic titers during strain improvement in both fungi.

Dataset Information

Screening and production of a potential extracellular fungal laccase from Penicillium chrysogenum: Media optimization by response surface methodology (RSM) and central composite rotatable design (CCRD).

Publications

Screening and production of a potential extracellular fungal laccase from <i>Penicillium chrysogenum</i>: Media optimization by response surface methodology (RSM) and central composite rotatable design (CCRD).

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets