Biopolymers have various applications in medicine, food and petroleum industries. The ascomycetous fungus Ophiocordyceps dipterigena BCC 2073 produces an exobiopolymer, a (1→3)-β-D-glucan, in low quantity under screening conditions. Optimization of O. dipterigena BCC 2073 exobiopolymer production using experimental designs, a scale-up in 5 liter bioreactor, analysis of molecular weight at different cultivation times, and levels of induction of interleukin-8 synthesis are described in this study.

To investigate the effects of dietary supplementation with different levels and molecular weights of fungal β-glucan on productive performances, health, carcass traits and meat quality in broilers. Two hundred and ten of one-day-old chicks with equal sex were assigned to seven experimental groups in 2×4 factorial arrangement. These groups were supplemented with (0, 10, 30 and 60 ppm) of molecular weight 1-3, 1-6 β-glucan (low or high). High molecular weight β-glucan (H: 943 kDa) was obtained from Ophiocordyceps dipterigena BCC 2073, whereas H with -Irradiation treatment was performed to achieve low molecular weight β-glucan (L: 8 kDa). There was no statistical significance in productive performances, apparent digestibility and interaction between fixed factors along 42 days of experiment (P>0.05). A higher caecal amylase activity was present in the group that received L, while there was a dramatic decrease in H and the control groups, respectively (P0.05). The supplementation of L at 30 ppm was suggested to achieve benefits of immune modulation without adverse effects on other parameters.

The serine protease of Bacillus sp. C-4 has been reported as candidate proteases in the degumming process of the silk industry. The optimization of protease production by Bacillus sp. C4 was carried out using two-level fractional factorial and central composite designs. The investigation was followed by laboratory and pilot-scale protease production using molasses in batch and fed-batch bioreactors to reduce the production cost. The highest protease activity observed (1546.5 U/mL, equivalent to 34.4 U/mL/h) in a 5-L bioreactor was obtained under fed-batch fermentation compared with batch process. The production of protease was subsequently scaled up to a pilot-scale 300-L fed-batch bioreactor, and a maximum protease activity of 1260 U/mL (28 U/mL/h) was observed. The degumming efficiencies of the protease produced by Bacillus sp. C4 in the CCD and bioreactors were 88.3% and 81.6%, respectively, relative to the alkaline degumming method. Furthermore, the stability test of the protease showed that the addition of CaCl₂ prolonged the stability of the protease activity from 4 to 8 weeks at room temperature. Furthermore, the protease can be conveniently preserved at room temperature for 1 month and at 4°C for more than 2 months without the addition of any chemicals/cryoprotectants.

The screening of exopolysaccharides (EPS) produced by 52 isolates of endophytic and basidiomycete fungi was studied on two different media, PDB and PYGM. There were five isolates that could produce dried exopolysaccharide of more than 4 g/L (S. commune LF01962, LF01001, LF01581, Pycnoporus sp. MMCR00271.1, Pestalotiopsis sp. PP0005). The molecular weights of these exopolymers were found to be in the range of 2.5–500 kDa. These five exopolysaccharides, produced by five different fungal isolates, showed non-cytotoxic activity against NCTC clone 929 and HDFn cell lines. The selected fungal isolate of S. commune LF01962 was used for further optimization of different medium compositions affecting exopolysaccharide production using statistical methods. Among four conditions tested in the first step (xylose + peptone, glucose + (NH₄)₂HPO₄, fructose + peptone, and mannose + yeast extract), mannose + yeast extract resulted in the highest exopolysaccharide production of 5.10 ± 2.00 g/L. In the second step using Plackett–Burman design, the optimal medium for S. commune exopolysaccharide production was found to consist of 40 g/L glucose, 5 g/L mannose, 20 g/L (NH₄)₂HPO₄, 5 g/L yeast extract, 3 g/L monosodium glutamate, 0.5 g/L KH₂PO₄, 0.5 g/L K₂HPO₄, 0.2 g/L MgSO₄, 1 mL/L trace elements, and 3 mL/L vitamin solution, which resulted in 8.16 g/L exopolysaccharide production. Exopolysaccharide production in a 5 L bioreactor using small pellets as seed inoculum was found to produce 18.28 g/L exopolysaccharide.

Phomalactone, an antibacterial, insecticidal, and herbicidal compound, was produced by insect pathogenic fungi, Ophiocordyceps communis BCC 1842 and BCC 2763, in bioreactors using different carbon and nitrogen sources. Glucose and fructose were preferable for growth and phomalactone production. The highest specific growth rate (μ) of 0.012 hr(-1), the highest biomass yield (Ysx) of 0.38 g DW g(-1) sugar, the highest volumetric sugar consumption rate (qs) of 0.036 g (L hr)(-1), the maximum phomalactone concentration ([Formula: see text]) of 93.30 mg L(-1) at 127 hr, and the highest volumetric production rate of phomalactone (qp) of 0.46 ± 0.12 mg (L d)(-1) were obtained on glucose and sodium nitrate as the sole carbon and nitrogen sources, respectively, by O. communis BCC 1842. In contrast, O. communis BCC 2763 gave lower phomalactone production. This mass phomalactone production is useful for the biological synthesis of a precursor for more broad-range potent analogs such as antitumor, antifungal, and others and for its further biological studies.