Use of Agro-Industrial Wastes for the Production of a Wild Yeast Enzyme with Disintegration Activity on Plant Tissues

Abstract The objective of the present study was to develop a cost-effective medium, using agro-industrial wastes for the production of a polygalacturonase by Wickerhanomyces anomalus of interest in cassava starch industries. The effect of several raw agro-industrial wastes and others nutrients on polygalacturonase production by W. anomalus, were evaluated, in a reference fermentation medium, using statistical designs, by batch culture. The ability of the cell-free supernatant to extract cassava starch was evaluated. Lemon peel was the best inducer for the production of PGase. Statistical analysis of the data showed that lemon peel, Mg+2 and PO4HK2 had significant effect on PGase production, and the others variables (yeast extract, Ca+2, Fe+2, amino acid and trace element solution) were no significant. PGase synthesis reached ~31 EUmL-1, in the OFM (glucose, lemon peel, urea, vitamins, KH2PO4 and MgSO4), after 12 h of culture, at a lab scale bioreactor. PGase of W. anomalus, was able to disintegrate cassava tuber tissue, and the starch granules contained within the cells were released into the reaction medium. Lemon peel can be used as inducer for PGase production by W. anomalus, in a low cost culture medium, appropriate for the production of the enzyme at large scale.

Cold-active pectinolytic activity produced by filamentous fungi associated with Antarctic marine sponges

BACKGROUND: Pectinase enzymes catalyze the breakdown of pectin, a key component of the plant cell wall. At industrial level, pectinases are used in diverse applications, especially in food-processing industry. Currently, most of the industrial pectinases have optimal activity at mesophilic temperatures. On the contrary, very little is known about the pectinolytic activities from organisms from cold climates such as Antarctica. In this work, 27 filamentous fungi isolated from marine sponges collected in King George Island, Antarctica, were screened as new source of cold-active pectinases. RESULTS: In semi-quantitative plate assays, 8 out 27 of these isolates showed pectinolytic activities at 15 °C and one of them, Geomyces sp. strain F09-T3-2, showed the highest production of pectinases in liquid medium containing pectin as sole carbon source. More interesting, Geomyces sp. F09-T3-2 showed optimal pectinolytic activity at 30 °C, 10 °C under the temperature of currently available commercial mesophilic pectinases. CONCLUSION: Filamentous fungi associated with Antarctic marine sponges are a promising source of pectinolytic activity. In particular, pectinases from Geomyces sp. F09-T3-2 may be potentially suitable for biotechnological applications needing cold-active pectinases. To the best of our knowledge, this is the first report describing the production of pectinolytic activity from filamentous fungi from any environment in Antarctica.

Influence of metal ions on pellet morphology and polygalacturonase synthesis by Aspergillus niger 3T5B8

The effects of cations addition on pellet morphology and polygalacturonase (PG) synthesis by Aspergillus niger 3T5B8 were studied and compared with a control system. Fe(II), Cu(II), Zn(II) and Mn(II) were added to the fermentation medium separately, and also as combined groups of cations. The addition of Fe2+ and/or Zn2+ ions was significantly positive to the enzyme production. A positive effect in the biomass content, however, was only obtained when the same metal ions were added separately. On the other hand, Cu2+ and Mn2+ ions had almost no effect on these parameters. The morphology of the pellets was studied by image processing techniques. Small pellets with small cores were usually obtained when Fe2+ and Zn2+ ions were individually or collectively added to the medium. The pellets produced in media containing Fe2+ or Zn2+ ions were compact, while the ones produced in a medium containing both cations were considered diffuse. Autolysis of the core was observed for large control pellets, due to the deficient nutrient transfer to the interior of the pellet. The pellets obtained in a medium containing both Fe2+ and Zn2+ ions were high enzyme producers, probably due to a loose morphology, induced by the presence of combined groups of metal ions in the medium, favoring the nutrient transfer.

Enhancement of polygalacturonase activity during auxin induced para nodulation and endorhizosphere colonization of Azospirillum in rice roots.

Effect of different auxins, namely, 2,4-dichlorophenoxyacetic acid (2,4-D), naphthalene acetic acid (NAA) and indole acetic acid (IAA) and Azospirillum brasilense bioinoculation on the enhancement of polygalacturonase (PG) activity in rice roots during para nodulation and endorhizosphere colonization of Azospirillum was studied under in vitro condition. It was observed that Azospirillum bioinoculation could augment PG activity of rice roots to a lesser extent without any root morphogenesis whereas auxin application together with Azospirillum bioinoculation enhanced PG activity of rice roots to a higher level which resulted in better root morphogenesis (para nodule) and endorhizosphere colonisation of A. brasilense. Among the three auxins tested, 2,4-D, even at lower concentration (0.5 ppm) enhanced the rice root PG activity, root morphogenesis and endorhizosphere colonization of Azospirillum while it was 2.0 ppm with NAA and variable with IAA. It is concluded that there is a positive correlation existing among PG activity, degree of root morphogenesis and endorhizosphere colonization of Azospirillum brasilense in rice roots and the degree of correlation is determined by the chemical composition, concentration and mode of action of the auxin utilised.

Sugar-cane juice induces pectin lyase and polygalacturonase in "Penicillium griseoroseum"

The use of other inducers as substitutes for pectin was studied aiming to reduce the production costs of pectin enzymes. The effects of sugar-cane juice on the production of pectin lyase (PL) and polygalacturonase (PG) by "Penicillium griseoroseum" were investigatedd. The Fungus was cultured in a mineral medium (ph 6.3) in a rotary shaker (150 rpm) for 48 h at 25§C. Culture media were supplemented with yeast extract and sucrose or sugar-cane juice. Sugar-cane juice added singly to the medium promoted higher PL activity and mycelical dry weight when compared to pectin and the use of sugar-cane juice and yeast extract or pectin. The results indicated that were similar to those obtained with sucrose-yeast extractor pectin. The results indicated that, even at low concentrations, sugar-cane juice was capable of inducing pectin lyase and polygalacturonase with no cellulase activity in "P. griseoroseum".

Partial purification of a polygalacturonase produced by solid-state cultures of Aspergillus niger 3T5B

A poligalacturonase produzida em cultura semi sólida de Aspergillus niger 3T5B8 foi purificada usando fracionamento por adiçäo de sal (salting out), diálise e cromatografia de gel-filtraçäo. A adiçäo de sulfato de amônio em diferentes níveis de saturaçäo apresentaram um compromisso entre purificaçäo e recuperaçäo da atividade enzimática. A cromatografia por gel-filtraç o forneceu bons resultados quando azida de sódio foi utilizada nos tampöes de eluiçäo, diminuindo as perdas na atividade enzimática em 14 por cento. O peso molecular determinado para esta poligalacturonase foi de 34700 daltons

Studies on pectin-degrading fungi in compost

The variation in temperature recorded during the composting process of garbage led to corresponding changes in the distribution of pectin decomposing fungi in the compost. It was found that total population and the spectrum of fungal species were sharply declined during the maximum temperature phase [68-70C] inside the pile. At 28C [mesophillic], 22 species belonging to 12 genera were isolated throughout the composting periods. The most common pectinophytic species were Aspergillus niger, Aspergillus flavus, Aspergillus terreus, Penicillium chrysogenum, Fusarium moniliforme, Alternaria alternata, Cladosporium cladosporioids and Trichoderma viride. At 45C, the total population declined sharply during the first two days of composting, then gradually increased till reaching the highest counts at the 35th day and decreased, thereafter. Aspergillus fumigatus, Aspergillus terreus, Aspergillus nidulans and Mucor pusillus were the most common species recovered on pectin plates at 45C. The relative pectinolytic activities of the isolated fungi at 28C revealed that, Aspergillus niger and Aspergillus flavus showed very strong polygalacturonase [PG] and pectin-methyl-esterase [PME] activities when grown on pectin containing medium. On the other hand, Aspergillus fumigatus and Aspergillus terreus were the strongest pectinolytic [PG and PME] fungal isolates at 45C

Effect of environmental conditions on the production of polygalacturonase by the edible mushroom [volvariella volvaceae]

Effect of environmental conditions including temperature, pH, shaking rate, ratio of medium to flask volume and inoculum percentage was studied to optimize conditions for the production of polygalacturonase by Volvariella volvaceae. No enzyme production was detected at 39C or when the fungus was grown under static conditions. The polygalacturonase enzyme was optimally produced at 34C, pH 4.5, 1% inoculum and 100 rpm shaking rate using two production media. The ratios between the medium to flask volume were 1: 3.3 and 1: 5 when the production medium contained 0.0008% CoCl2 or 0.525% MgSO4.7H2O, respectively