Wai Prathumpai

This study used amperometric electrochemical sensing on a commercially unmodified non-enzymatic screen-printed carbon electrode (0.1 V, 50 mV s⁻¹) to monitor real-time α-amylase hydrolysis of native, acetylated-modified, and thermally treated tapioca starch at 0–60 min, 40 and 50 °C, and pH 5.0 and 7.0. The glucose obtained was comparable with that obtained from the spectrophotometric method, with R² values ranging from 0.85 to 0.99 and statistically significant differences (p < 0.05) in most of the studied conditions. The electrochemical method suggests that SPCE is a potential low-cost alternative method for monitoring the kinetics of starch hydrolysis in the food industry.

Twenty strains of Schizophyllum commune from the BIOTEC culture collection were selected for this study. S. commune is characterized by white to gray fan-shaped caps with lobed margins and distinctive split gills. Phylogenetic analysis of combined LSU rDNA and ITS rDNA sequences data using maximum parsimony placed the fungi in a strongly supported clade with S. commune. All strains were primarily screened for exopolysaccharide (EPS) and biomass production using potato dextrose broth (PDB) and peptone yeast glucose medium (PYGM) in 250 mL flasks shaken at 200 rpm for 7 days. The results revealed three strains with high EPS production, each exceeding 2.3 g/L, namely MMCR00487, MMCR00474 and MMCR00256. These strains were selected for media optimization using a Plackett–Burman design. Among them, MMCR00256 exhibited the highest EPS yield of 8.34 ± 1.47 g/L, followed by MMCR00487 and MMCR00474. Therefore, the strain MMCR00256 was further optimized by central composite design. The results revealed that the optimized medium for MMCR00256 increased the production of EPS to 10.39 ± 1.69 g/L, with a biomass yield of 26.28 ± 1.63 g/L (395 mg/g). The 5 L bioreactor optimization tested two inoculum types (mycelial and pellet) and two media (CCD and estimated) using strain MMCR00256. The mycelial inoculum grown in the estimated medium produced the highest EPS yield of 8.37 ± 0.26 g/L after 3 days, with 13.56 ± 2.94 g/L biomass. In conclusion, this study demonstrates that S. commune MMCR00256, when cultivated using the estimated medium and mycelial inoculum, can achieve enhanced exopolysaccharide production with improved efficiency, highlighting its significant potential for the development of efficient and scalable schizophyllan production processes at the industrial scale. Furthermore, this study provides essential insights into the cultivation and optimization of schizophyllan in S. commune.

β‐1,3/1,6‐glucan is an immune‐modulating functional ingredient. To enhance solubility, β‐1,3/1,6‐glucan oligosaccharides were developed from polysaccharides through gamma‐irradiation. Nevertheless, whether their safety and efficacy profiles are different remains unclear. Our previous study identified 2000 mg/day as the maximum short‐term tolerable dose of Ophiocordyceps dipterigena BCC2073‐derived β‐1,3/1,6‐glucan oligosaccharides and polysaccharides. However, the long‐term safety of this dosage was unknown. This randomized, blinded, placebo‐controlled trial was conducted to evaluate their safety over 12 weeks. Ninety‐six healthy participants were randomly assigned to receive 2000 mg daily of either β‐glucans oligosaccharides, β‐glucans polysaccharides, or placebo capsules ( n = 32 each group). Adverse symptoms, changes in body weight, defecation, hematological, and biochemical parameters, vital signs, and heart function were assessed using subject diaries, interviews, blood and urine tests, and electrocardiograms. No serious adverse events or changes in body weight, liver or renal function, complete blood counts, blood glucose levels, urinalysis, or electrocardiogram were observed in any of the groups. Notably, supplementation with β‐glucan oligosaccharides, but not polysaccharides, resulted in significant reductions in total cholesterol and LDL levels compared to the control group. Only the polysaccharides group had significant positive (easier defecation) and negative (constipation, loose stools) defecation‐related symptoms. The negative symptoms (found in 3%–19% of participants) were mild. These findings indicate that daily supplementation with 2000 mg of β‐1,3/1,6‐glucan oligosaccharides or polysaccharides for 12 weeks is safe in healthy individuals. The oligosaccharides demonstrated superior lipid‐lowering efficacy with fewer adverse events compared to the polysaccharides. Possible defecation‐related side effects of β‐1,3/1,6‐glucan polysaccharides should be considered. Trial Registration: Thai Clinical Trial Registry: TCTR20240622005

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.

Vip3A (vegetative insecticidal protein) is a representative member of the Vip3 family, which is widely used for lepidopteran pest control. This Vip3A protein, a non-growth-associated protein, is an effective bioinsecticide against insect pests, but there is relatively little information about its production processes at large scales. Hence, the effects of environmental factors on Vip3A production by Bacillus thuringiensis Bt294 (antifoam agents, shaking speeds, agitation and aeration rates), as well as controlling physical conditions such as the lowest point of dissolved oxygen and controlling of culture pH, were observed in shaking flasks and bioreactors. The results showed that antifoam agents, flask types and shaking speeds had significant effects on Vip3A and biomass production. Cultivation without pH control and DO control in 5 L bioreactors at lower agitation and aeration rates, which was not favorable for biomass production, resulted in a high Vip3A protein production of 5645.67 mg/L. The scale-up studies of the Vip3A protein production in a pilot-scale 750 L bioreactor gave 3750.0 mg/L. Therefore, this study demonstrated the significant effects of agitation, aeration rates and culture pH on Vip3A production by B. thuringiensis Bt294. Balancing of physical conditions was necessary for obtaining the highest yield of Vip3A by slowing down the production rate of biomass. Moreover, this Vip3A protein has high potential as a bioinsecticide for lepidopteran pest control in organic crops. This information will be important for significantly increasing the Vip3A protein concentration by the bacterium and will be useful for field application at a lower cost.

Cordycepin is one of the most important bioactive compounds; the low productivity and long production cycle of cordycepin are barriers to its commercialization. The optimal media for cordycepin production by Cordyceps militaris BCC 2819 and Cordyceps cicadae BCC 19788, which are potent cordycepin-producing-fungal strains, were determined through statistical experiments. Six nutrients including glucose, adenine, glycine, alanine, casein hydrolysate and vitamin solution were found to influence the cordycepin production by C. militaris BCC 2819, while the same factors were found for the cordycepin production by C. cicadae BCC 19788 except glucose that was replaced by ammonium sulfate. The highest cordycepin production of 1,176.69 ± 263.33 mg/L was obtained by C. militaris BCC 2819 using the central composite design. The highest cordycepin production of 4,259.63 ± 224.20 mg/L was obtained by C. cicadae BCC 19788 using the central composite design. Cordycepin production in 5-L fed-batch fermentation by C. militaris BCC 2819 and C. cicadae BCC 19788 using optimized medium reached maximum production levels of 3,112.50 and 3,587.10 mg/L, respectively, accounted for more than 1.2-fold compared to those in batch fermentation. Furthermore, the highest levels of the bioactive compounds; exopolysaccharide, adenosine and mannitol produced by C. militaris BCC 2819 were 43.90 ± 2.51 g/L, 2,897.40 ± 382.47 mg/L and 5,981.10 ± 254.72 mg/L, respectively. The highest levels of the bioactive compounds; exopolysaccharide, adenosine and mannitol produced by C. cicadae BCC 19788 were 38.10 ± 2.84 g/L, 3,78520 ± 165.70 mg/L and 6,100.20 ± 191.14 mg/L, respectively. These results demonstrated the new isolates produced high amounts of bioactive compounds, especially cordycepin. Interestingly, this process can be applied for cordycepin production for future applications or scale-up studies. Key words: Batch fermentation, cordycepin, Cordyceps militaris, fed-batch fermentation, Cordyceps cicadae, optimization. Cordycepin is one of the most important bioactive compounds; the low productivity and long production cycle of cordycepin are barriers to its commercialization. The optimal media for cordycepin production by Cordyceps militaris BCC 2819 and Cordyceps cicadae BCC 19788, which are potent cordycepin-producing-fungal strains, were determined through statistical experiments. Six nutrients including glucose, adenine, glycine, alanine, casein hydrolysate and vitamin solution were found to influence the cordycepin production by C. militaris BCC 2819, while the same factors were found for the cordycepin production by C. cicadae BCC 19788 except glucose that was replaced by ammonium sulfate. The highest cordycepin production of 1,176.69 ± 263.33 mg/L was obtained by C. militaris BCC 2819 using the central composite design. The highest cordycepin production of 4,259.63 ± 224.20 mg/L was obtained by C. cicadae BCC 19788 using the central composite design. Cordycepin production in 5-L fed-batch fermentation by C. militaris BCC 2819 and C. cicadae BCC 19788 using optimized medium reached maximum production levels of 3,112.50 and 3,587.10 mg/L, respectively, accounted for more than 1.2-fold compared to those in batch fermentation. Furthermore, the highest levels of the bioactive compounds; exopolysaccharide, adenosine and mannitol produced by C. militaris BCC 2819 were 43.90 ± 2.51 g/L, 2,897.40 ± 382.47 mg/L and 5,981.10 ± 254.72 mg/L, respectively. The highest levels of the bioactive compounds; exopolysaccharide, adenosine and mannitol produced by C. cicadae BCC 19788 were 38.10 ± 2.84 g/L, 3,78520 ± 165.70 mg/L and 6,100.20 ± 191.14 mg/L, respectively. These results demonstrated the new isolates produced high amounts of bioactive compounds, especially cordycepin. Interestingly, this process can be applied for cordycepin production for future applications or scale-up studies. Key words: Batch fermentation, cordycepin, Cordyceps militaris, fed-batch fermentation, Cordyceps cicadae, optimization.

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.

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.