Response surface methodology study of laccase production in Panus tigrinus liquid cultures

Enrichment of laccase production by Phoma herbarum isolate KU4 under solid-state fermentation by optimizing RSM coefficients using genetic algorithm

The process parameters were optimized to obtain enhanced enzyme activity from the fungus Phoma herbarum isolate KU4 using rice straw and saw dust as substrate under solid-state fermentation using Response surface methodology (RSM). Genetic algorithm was used to validate the RSM for maximum laccase production. Six variables, viz., pH of the media, initial moisture content, copper sulphate concentration, concentration of tannic acid, inoculum concentration and incubation time were found to be effective and optimized for enhanced production. Maximum laccase production was achieved by RSM at pH 5·0 and 86% of initial moisture content of the culture medium, 150 µmol l^-1 of CuSO₄ , 1·5% tannic acid and 0·128 g inoculum g^-1 dry substrate inoculum size on the fourth day of fermentation. The highest laccase activity was observed as 79 008 U g^-1 , which is approximately sixfold enhanced production compared to the unoptimized condition (12 085·26 U g^-1 ).

Enhancing laccase production by white-rot fungus Funalia floccosa LPSC 232 in co-culture with Penicillium commune GHAIE86

To obtain enzymatic preparations with higher laccase activity levels from Funalia floccosa LPSC 232, available for use in several applications, co-cultures with six filamentous microfungi were tested. A laccase non-producing soil fungus, identified as Penicillium commune GHAIE86, showed an outstanding ability to increase laccase activity (3-fold as compared to that for monoculture) when inoculated in 6-day-old F. floccosa cultures. Maximum laccase production with the F. floccosa and P. commune co-culture reached 60 U/mL, or twice that induced by chemical treatments alone. Our study demonstrated that co-culture with soil fungi might be a promising method for improving laccase production in F. floccosa. Although the enhancement of laccase activity was a function of P. commune inoculation time, two laccase isoenzymes produced by F. floccosa remained unchanged when strains were co-cultured. These data are compatible with the potential of F. floccosa in agricultural applications in soil, whose enzyme machinery could be activated by soil fungi such as P. commune.

Downstream process development strategies for effective bioprocesses: Trends, progress, and combinatorial approaches

The biopharmaceutical industry is at a turning point moving toward a more customized and patient-oriented medicine (precision medicine). Straightforward routines such as the antibody platform process are extended to production processes for a new portfolio of molecules. As a consequence, individual and tailored productions require generic approaches for a fast and dedicated purification process development. In this article, different effective strategies in biopharmaceutical purification process development are reviewed that can analogously be used for the new generation of antibodies. Conventional approaches based on heuristics and high-throughput process development are discussed and compared to modern technologies such as multivariate calibration and mechanistic modeling tools. Such approaches constitute a good foundation for fast and effective process development for new products and processes, but their full potential becomes obvious in a correlated combination. Thus, different combinatorial approaches are presented, which might become future directions in the biopharmaceutical industry.

Impact of laccase enzyme inducers on solid waste compost maturity and stability

The influence of inducers of laccase produced by Pleurotus ostreatus-P1 on the physicochemical properties of solid waste compost was investigated. In order to examine the degree of humification and time period for maturity and stability of compost, three different treatments (T: laccase; T1: laccase+CuSO4; and T2: laccase+CuSO4+CaCl2) were inoculated on solid waste in the initial stage of the composting process. During the composting process, the carbon nitrogen ratio (C/N), nitrate ([Formula: see text]), ammonium nitrogen ([Formula: see text]), cation exchange capacity (CEC), humic acid (HA) and fulvic acid (FA) humification rate (HR), Humification Index (HI), and degree of polymerization (DP) were assessed for the evaluation of compost maturity and stability, and it was found that T2 treatment C/N, CEC, and HI was greater, 46.8%, 37.2%, and 38.46%, respectively, than T at the end of the maturation phase. Optimum degree of maturity was also appraised by the Germination Index, 98.25% was attained by T2, whereas 88.65% and 71.23% by T1 and T, respectively. Significant Pearson correlation was also found between compost characteristics such as C/N, CEC, HA, FA, DP, HI, and HR. In addition, also obstinate the mineralization's of nitrogen under laboratory incubation, using soil amended by 50 and 100 kg-N/ha and examined an increasing trend in nitrogen mineralization with the application rate. Moreover, it was concluded that the laccase inducers increase the disintegration and humification process during solid waste composting.

Chlorobenzoic acid degradation by Lentinus (Panus) tigrinus: in vivo and in vitro mechanistic study-evidence for P-450 involvement in the transformation

Aim of this work was to investigate the ability of Lentinus (Panus) tigrinus to degrade and detoxify a chlorobenzoate (CBA) mixture composed of mono-, di- and tri-chlorinated isomers. The degradation process was investigated as a function of both the growing medium (i.e. low N Kirk's and malt extract-glucose medium) and cultivation conditions (i.e. stationary and shaken cultures). The majority of CBAs were quantitatively degraded within the early 15 d from spiking with the notable exception of the double ortho-chlorinated compounds, 2,6-di-, 2,3,6-tri- and 2,4,6-tri-CBA. Analysis of the degradation intermediates indicated the occurrence of side chain reduction, hydroxylation and methylation reactions. Although CBAs stimulated laccase production, in vitro experiments with a purified L. tigrinus laccase isoenzyme demonstrated its inability to participate in the initial attack on CBAs even in the presence of redox mediators; similar results were found with a Mn-peroxidase isoenzyme. Conversely, prompt degradation was observed upon 1h incubation of CBAs with a purified microsomal fraction containing cytochrome P-450 monooxygenase. The nature of some reaction products (i.e. hydroxylated derivatives), the dependency of the reaction on NADPH and its susceptibility to either CO or piperonyl butoxide inhibition confirmed the involvement of L. tigrinus cytochrome P-450 in the early steps of CBA degradation.

Laccase production by Trametes versicolor under limited-growth conditions using dyes as inducers

Laccase production by pre-growth pellets of Trametes versicolor using two types of textile dyes as inducers was studied. By decoupling the enzyme production phase from the growth phase, it is possible to reduce the time and nutrients required for laccase production. At the glucose maintenance level, the effect of the nitrogen source and textile dye was analysed using response surface methodology. Ammonium chloride was used as the inorganic nitrogen source. Two types of dyes were tested: Grey Lanaset G (GLG), a metal complex dye mixture containing nitrogen; and Alizarin Red (AR), an anthraquinonic dye with no nitrogen in its chemical structure. GLG induces laccase production at a higher extent than AR. Despite the limiting conditions required for the production of laccase, enzyme production increases with increasing ammonium chloride. When AR, the N-free dye, was used as an inducer, the optimal supply of N for laccase production was 1.2 mg/(g dry cell weight x d) as ammonium chloride. The reuse of fungal pellets in the repeated-batch mode under maintenance conditions was found to be a good strategy for improving laccase production, as enzyme production increased to up to seven times the production of the first cycle. It was demonstrated that GLG can be used as an inducer and as an N source and, thus, it is possible to decolorize the dye and to induce laccase production at the same time without adding an extra N source.

Optimization of ligninolytic enzyme activity and production rate with Ceriporiopsis subvermispora for application in bioremediation by varying submerged media composition and growth immobilization support

Response surface methodology (central composite design of experiments) was employed to simultaneously optimize enzyme production and productivities of two ligninolytic enzymes produced by Ceriporiopsis subvermispora. Concentrations of glucose, ammonium tartrate and Polysorbate 80 were varied to establish the optimal composition of liquid media (OLM), where the highest experimentally obtained activities and productivities were 41 U L⁻¹ and 16 U L⁻¹ day⁻¹ for laccase (Lac), and 193 U L⁻¹ and 80 U L⁻¹ day⁻¹ for manganese peroxidase (MnP). Considering culture growth in OLM on various types of immobilization support, the best results were obtained with 1 cm beech wood cubes (BWCM). Enzyme activities in culture filtrate were 152 U L⁻¹ for Lac and 58 U L⁻¹ for MnP, since the chemical composition of this immobilization material induced higher Lac activity. Lower enzyme activities were obtained with polyurethane foam. Culture filtrates of OLM and BWCM were applied for dye decolorization. Remazol Brilliant Blue R (RBBR) was decolorized faster and more efficiently than Copper(II)phthalocyanine (CuP) with BWCM (80% and 60%), since Lac played a crucial role. Decolorization of CuP was initially faster than that of RBBR, due to higher MnP activities in OLM. The extent of decolorization after 14 h was 60% for both dyes.