Evaluation of agricultural byproducts for the production of betaglucosidase by Aspergillus niger MBT-2 using solid state fermentation

The experiment was conducted to isolate and screen fungal strain and optimization of solid-state fermentation conditions for enhanced production of β-glucosidase. Different fungal cultures were isolated and screened for β-glucosidase production. The physicochemical and nutritional parameters were optimized for enhanced production of β-glucosidase from higher producer. Among all the isolates the isolate which exhibited highest β-glucosidase potential was identified and assigned the code as Aspergillus niger MBT-2. The optimum β-glucosidase production was obtained in M5 medium containing wheat bran after 72 hrs of incubation at 40°C, pH 6 and 20 ml of moisture contents. In addition to this 2% fructose and 2% yeast extract proved to be best carbon and nitrogen sources, respectively and gave maximal enzyme productivity. The exploitation of agricultural by products as a substrate reduced the production cost of enzyme and makes the process economical. The Aspergillus niger MBT-2 has promising potential of bioconversion of low-cost material into valuable product like β-glucosidase.

Vitreoscilla sp. hemoglobin (VHb) Expression in Heterologous Hosts: Some Aspects of Their Biotechnological Application

It is worth mentioning that the high output of different physiological responses under the expression of vgb, may have a considerable effect on the enzyme productivity, dairy industry, heavy metal uptake, biodegradation of different organic pollutants and other applications. The expression of bacterial haemoglobin is useful in lessening the load of perceived toxic conditions such as high oxygen levels. This in turn probably has the same impact on some peripheral toxic materials. This, hemoglobin biotechnology can be extended to enhance production of pollutants degrading enzymes or production of some valuable manufacturing materials on the case-by-case bases. It is likely that the mechanism of bacterial hemoglobin (VHb) effects is intermediated via an oxygen trapping action. This may drive the enrichment of ATP production, which is mostly required for higher productivity of needed substances for that activity.

IN VITRO SCREENING OF CELL WALL DEGRADING ENZYME PRODUCTIVITY FROM FUNGAL CULTURE FILTRATES ON DEPROTEINISED PLANT FLUID BY CUP PLATE ASSAY

The present study purpose is to evaluate the potentiality of the Deproteinised juice made from selected plants to induce the enzyme productivity by growing the fungi on it. It is because, in earlier findings, the DPJ was found potential in enhancing fungi and the plant growth when used as the medium. The internal factors are responsible in DPJ which induces plants and fungi growth. During the process of Green Crop Fractionation (GCF), the deproteinised (DPJ) obtained from tissues of cabbage, beet, lucerne (Alfalfa), carrot and Anathum (Dill) forages left after leaf protein extraction employed as a medium for the cultivation of mycelial biomass of Penicillium and Aspergillus fungi. The mycelial growth in vitro was compared with the glucose nitrate medium. The culture filtrates were used to screen different secreted hydrolytic or cell wall degrading enzymes.. The agar ‘cup‐plate’ diffusion technique has been applied to the quantitative determination of enzyme activity, principally to amylase, cellulase and protease. With all enzymes so far examined, the relationship between diameter of zone over a wide range secreted quantitatively was examined. All fungi grew well on DPJ in comparison to their growth on glucose nitrate (GN) medium. Comparatively with GN medium, lucerne DPJ was found having more mycelial cellular proliferation. When the fungi grown on different concentrations of substrates, enriched with carboxymethyl cellulose, casein and starch in deproteinised leaf extracts and GN medium, it was found that there was the enhancement in the mycelial dry weight grown on DPJ as compared with glucose nitrate medium. Penicillium showed more yield of enzyme activities especially of cellulases and amylases as compared to protease by cup plate method. There was enhancement of mycelial biomass when the concentrations of substrates increased from 1% to 2%, while there was no change in the activity of all enzymes by increasing the concentrations of substrates. Activities of the enzymes in vitro can be indicative of the pattern of organogenesis in callus cultures in further studies by fungal culture filtrates cultured on deproteinised fluid medium.

Production of polygalacturonase by Aspergillus niger BC23 isolated from Irvingia gabonensis (African mango) fruit

Polygalacturonase was produced from Aspergillus niger BC 23 which was isolated from spoiled Irvingia gabonensis fruit. The influence of carbon substrates on enzyme production showed that the medium containing sucrose produced a maximum enzyme yield of 38.5 U/mg protein after 72 h. Enzyme productivity in this medium was much higher than in the medium that contained only citrus pectin as the sole carbon source. Medium containing yeast extract as a nitrogen source caused the production of specific enzyme activity of 31.2 U/mg protein. Results on the effect of metal ions on enzyme activity showed that Ca2+ gave a percent relative activity of 214% in comparison to the native enzyme activity. The enzyme showed maximum activity in slight acid and neutral pH media with optimal activity at pH 4.0. Temperature activity profile of the enzyme showed best activity at a temperature of 35?C. Dried fruit peels were tested for their abilities to support enzyme production in a media devoid of citrus pectin. The best enzyme productivity of 102.3 U/mg protein was achieved after 72 h in the medium containing orange peel and this level was much higher than that achieved when pure carbon sources or citrus pectin alone were used for enzyme production.

Studies on the production of glucose isomerase by Bacillus licheniformis

This work reports the effects of some culture conditions on the production of glucose isomerase by Bacillus licheniformis. The bacterium was selected based on the release of 3.62 mg/mL fructose from the fermentation of glucose. Enzyme was produced using a variety of carbon substrates but the highest enzyme activity was detected in a medium containing 0.5% xylose and 1% glycerol (specific activity = 6.88 U/mg protein). Media containing only xylose or glucose gave lower enzyme productivies (specific activities= 4.60 and 2.35 U/mg protein respectively). The effects of nitrogen substrates on glucose isomerase production showed that yeast extract supported maximum enzyme activity (specific activity = 5.24 U/mg protein). Lowest enzyme activity was observed with sodium trioxonitrate (specific activity = 2.44 U/mg protein). In general, organic nitrogen substrates supported higher enzyme productivity than inorganic nitrogen substrates. Best enzyme activity was observed in the presence of Mg2+ (specific activity = 6.85 U/mg protein) while Hg2+ was inhibitory (specific activity = 1.02 U/mg protein). The optimum pH for best enzyme activity was 6.0 while optimum temperature for enzyme production was 50ºC.

Optimum conditions for Inulinase production by Aspergillus niger using solid state fermentation

Thirty local fungal isolates according to Aspergillus niger were screened for Inulinase production on synthetic solid medium depending on inulin hydrolysis appear as clear zone around fungal colony. Semi-quantitative screening was performed to select the most efficient isolate for inulinase production. the most efficient isolate was AN20. The optimum condition for enzyme production from A. niger isolate was determined by busing a medium composed of sugar cane moisten with corn steep liquor 5;5 (v/w) at initial pH 5.0 for 96 hours at 30 0C . Enzyme productivity was tested for each of the yeast Kluyveromyces marxianus, the fungus A. niger AN20 and for a mixed culture of A. niger and K. marxianus. The productivity of A. niger gave the highest specific activity of 153 U/mg, as compared with K. marxianus which gave 86 U/mg.

Screening for fibrinolytic filamentous fungi and enzymatic properties of the most potent producer, Aspergillus brasiliensis AUMC 9735

A potential screening programme for fibrinolytic filamentous fungi in the Egyptian environment was done for the first time. The proteolytic activity was positive in 38.5% of isolates, whilst only thirty-four of them were able to produce fibrinolytic enzymes. The two most potent isolates were identified as Aspergillus brasiliensis AUMC 9735 and Aspergillus flavus AUMC 9736. Under submerged culture conditions, the two strains were able to excrete fibrinolytic enzymes, reaching a maximum at 5 and 9 days, respectively. Maximal enzyme productivity by both strains was achieved by lactose and sucrose, respectively. All tested nitrogen sources were stimulatory for enzyme production by both strains, except for ammonium acetate in the case of A. brasiliensis AUMC 9735. Purification of A. brasiliensis AUMC 9735 enzyme increased its specific activity to 83.5-fold with a recovery of 9.1% and molecular weight of 40 kDa. Maximal activity was recorded at pH 8 (stability at pH 6-11). The purified enzyme showed higher thermostability than most fibrinolytic enzymes of filamentous fungi with the midpoint temperature (T