Potential of Fermentable Sugar Production from Napier cv. Pakchong 1 Grass Residue as a Substrate to Produce Bioethanol

AbstractBioethanol is one of the most significant renewable fuels. The major sources of bioethanol production are food crops such as corn, sugarcane, rice, wheat and sugar beet. However, utilization of food crops to produce bioethanol could affect the food sources and disrupt the food to population ratio. To overcome these issues, the utilization of lignocellulosic materials such as wheat straw, grass and crop residues to produce bioethanol has been developed for second-generation fuel, since those resources are abundant, cheap and renewable. Napier Pakchong 1 grass (NPG) residue is a lignocellulosic waste obtained from the process of biogas production that can be used as an alternative material for bioethanol production. This research aims to study on the potential of fermentable sugar production from NPG residue. The materials were pretreated with different concentrations of sodium hydroxide (NaOH), followed by enzymatic hydrolysis for saccharification. The results suggested that pretreatment with 3.0% (w/v) NaOH solution at 121̊C for 60 minutes provided the highest lignin removal of 86.1% (w/w) and enriched cellulose fraction from 36.4 to 75.6% (w/w). The enzymatic hydrolysis was conducted by varying enzyme loading volume and total solid contents (TS) at pH 4.8, 50̊C for 72h. The hydrolysis with enzyme loading volume of 2.0 ml/g of substrate and 10% (w/v) of TS were optimal for saccharification giving the reducing sugar yield of 768 mg/g of pretreated biomass or equal to 64 g/L and glucose yield of 522 mg/g of pretreated biomass or equal to 43 g/L. The reducing sugar will be used as a starting material for yeast to produce bioethanol

ENZYMATIC PRODUCTION OF XYLOOLIGOSACCHARIDES FROM CORNCOB USING ENDO-XYLANASE FROM Streptomyces thermovulgaris TISTR1948

Abstract Xylooligosaccharides (XOs) are the sugar oligomers produced from xylan hydrolysis. XOs have a characteristic of prebiotic by promoting the growth of probiotic microorganisms. Xylan containing agricultural wastes e.g. rice straw, sugarcane bagasse and corncob could be applied to produce XOs by a consecutively process of alkali-pretreatment and enzymatic hydrolysis. In this study, we emphasized on enzymatic production of XOs from corncob, a low cost raw material and relatively high xylan content. The dried corncob was ground and sieved to be <100 mesh size, then subjected to alkali-pretreatment by soaking in 10.0% (w/v) KOH solution at 100°C for 1 h, followed by adjusting pH to 7.0 by adding 5.0% (w/v) H 2 SO 4 , washed by tap water, filtered through a filter cloth and dried the filtrate at 80°C for 48 h. The recovery yield after KOH-pretreatment was 43.69±1.30% (w/w) and the major components of KOH-pretreated corncob were; cellulose (68.21±1.41%), hemicellulose (21.67±0.71%) and lignin (4.29±0.40%). The KOH-pretreated corncob was then subjected to enzymatic hydrolysis by mashing with 10 mM K-P buffer pH 6.5 (15.0% solid). Then, 100 U/g substrate of endo-xylanase from Streptomyces thermovulgaris TISTR1948 was added, the reaction was carried out at 55°C under static condition for 24 h. The samples were periodically taken and analyzed by a thin-layer chromatography (TLC). The results revealed that the suitable reaction time for XOs production was 12 h, which the xylobiose was found as the main product while few xylose contents were obtained. The optimal conditions for XOs production was studied by the response surface methodology (RSM) via the central composite design (CCD). The factors of pH and temperature (°C) were investigated with endo-xylanase concentration (U/g substrate). The results showed that all factors were significant and influenced on the quantity of XOs in term of reducing sugar content (mg/g substrate). The optimal conditions to achieve maximum yield of reducing sugar were; endoxylanase concentration 142.70 U/g substrate at 53.56°C and pH 6.51. Using this experimental design, the reducing sugar content increased from 109.89±1.87 to 130.83±1.4 mg/g substrate or 603.74±6.49 mg/g xylan content in KOH-pretreated corncob which was 19.09% higher than un-optimized condition

The antiviral activity of bacterial, fungal, and algal polysaccharides as bioactive ingredients: Potential uses for enhancing immune systems and preventing viruses

Viral infections may cause serious human diseases. For instance, the recent appearance of the novel virus, SARS-CoV-2, causing COVID-19, has spread globally and is a serious public health concern. The consumption of healthy, proper, functional, and nutrient-rich foods has an important role in enhancing an individual's immune system and preventing viral infections. Several polysaccharides from natural sources such as algae, bacteria, and fungi have been considered as generally recognized as safe (GRAS) by the US Food and Drug Administration. They are safe, low-toxicity, biodegradable, and have biological activities. In this review, the bioactive polysaccharides derived from various microorganisms, including bacteria, fungi, and algae were evaluated. Antiviral mechanisms of these polysaccharides were discussed. Finally, the potential use of microbial and algal polysaccharides as an antiviral and immune boosting strategy was addressed. The microbial polysaccharides exhibited several bioactivities, including antioxidant, anti-inflammatory, antimicrobial, antitumor, and immunomodulatory activities. Some microbes are able to produce sulfated polysaccharides, which are wellknown to exert a board spectrum of biological activities, especially antiviral properties. Microbial polysaccharide can inhibit various viruses using different mechanisms. Furthermore, these microbial polysaccharides are also able to modulate immune responses to prevent and/or inhibit virus infections. There are many molecular factors influencing their bioactivities, e.g., functional groups, conformations, compositions, and molecular weight. At this stage of development, microbial polysaccharides will be used as adjuvants, nutrient supplements, and for drug delivery to prevent several virus infections, especially SARS-CoV-2 infection

Evaluation of cell disruption for partial isolation of intracellular pyruvate decarboxylase enzyme by silver nanoparticles method

Candida tropicalis TISTR 5350 was used in the comparison of seven concentration levels of silver nanoparticles (0, 5, 10, 15, 20, 25, and 30 μg ml–1) for cell disruption methods. The optimized cell disruption strategy was selected based on the optimal protein yield and biological activity. The maximum volumetric and specific pyruvate decarboxylase (PDC, EC 4.1.1.1) activities (0.53±0.05 U ml–1 and 0.17±0.02 U mg–1 protein, respectively) were observed at 15 μg ml–1 silver nanoparticles. The silver nanoparticle concentration level of 15 μg ml–1 was investigated further by comparing the reaction mixtures at different time intervals of 0, 1, 2, 3, 4, 5, and 6 min. The result showed that the highest specific PDC activity of 0.39±0.01 U mg–1 protein was obtained from mixing for 3 min. This was not significantly different (P≤0.05) from other mixing time intervals

การสังเคราะห์ชูการ์เอสเทอร์จากน้ำมันปาล์มและกรดไขมันที่ได้จากการทำบริสุทธิ์น้ำมันปาล์มโดยใช้เอนไซม์ไลเปสจากแบคทีเรียสองชนิด

Thesis (Ph.d., Biotechnology)--Prince of Songkla University, 200

Enhancement of carotenoids and lipids production by oleaginous red yeast <i>Sporidiobolus pararoseus</i> KM281507

<p>Bioconversion of biodiesel-derived crude glycerol into carotenoids and lipids was investigated by a microbial conversion of an oleaginous red yeast <i>Sporidiobolus pararoseus</i> KM281507. The methanol content in crude glycerol (0.5%, w/v) did not show a significant effect on biomass production by strain KM281507. However, demethanolized crude glycerol significantly supported the production of biomass (8.64 ± 0.13 g/L), lipids (2.92 ± 0.03 g/L), β-carotene (15.76 ± 0.85 mg/L), and total carotenoids (33.67 ± 1.28 mg/L). The optimal conditions suggested by central composite design were crude glycerol concentration (55.04 g/L), initial pH of medium (pH 5.63) and cultivation temperature (24.01°C). Under these conditions, the production of biomass, lipids, β-carotene, and total carotenoids were elevated up to 8.83 ± 0.05, 4.00 ± 0.06 g/L, 27.41 ± 0.20, and 53.70 ± 0.48 mg/L, respectively. Moreover, an addition of olive oil (0.5 − 2.0%) dramatically increased the production of biomass (14.47 ± 0.15 g/L), lipids (6.40 ± 0.09 g/L), β-carotene (54.43 ± 0.95 mg/L), and total carotenoids (70.92 ± 0.51 mg/L). The oleic acid content in lipids was also increased to 75.1% (w/w) of total fatty acids, indicating a good potential to be an alternative biodiesel feedstock. Meanwhile, the β-carotene content in total carotenoids was increased to 76.7% (w/w). Hence, strain KM281507 could be a good potential source of renewable biodiesel feedstock and natural carotenoids.</p

Antigenotoxic Effects and Possible Mechanism of Red Yeast (Sporidiobolus pararoseus) on Aflatoxin B1-Induced Mutagenesis

Red yeast (Sporidiobolus pararoseus), obtained from glycerol waste in the biodiesel process, has been used as a mycotoxin sorbent in some agricultural products. This study focused on the antigenotoxic effects of red yeast on aflatoxin B1 (AFB1)-induced mutagenesis, using a Salmonella mutation assay and a rat liver micronucleus test. Red yeast was sequentially extracted to obtain hexane, acetone, hot water, and residue fractions. Carbohydrates were mainly found in hot water extract (HWE), while proteins were observed in the residue fraction. The amount of lycopene in hexane extract (HE) was higher than the amount of β-carotene in HE. All red yeast extracts were not mutagenic in the Salmonella typhimurium strains TA98 and TA100 under the presence and absence of metabolic activation. Among the extracts obtained from red yeast, HE presented the strongest antimutagenicity against AFB1-induced mutagenesis in both strains, but HWE did not show any antimutagenicity. The oral administration of red yeast, HE, and HWE for 28 days was further investigated in rats. These extracts did not induce micronucleated hepatocytes. Furthermore, they modulated the activities of some detoxifying enzymes but did not alter the activities of various cytochrome P450 isozymes. Notably, they significantly decreased hepatic micronucleus formation in AFB1-initiated rats. HE altered the activity of hepatic glutathione-S-transferase but did not affect its protein expression. Taken together, the antigenotoxicity of red yeast against AFB1-induced mutagenesis might be partly due to the modulation of some detoxifying enzymes in AFB1 metabolism. β-Carotene and lycopene might be promising antigenotoxic compounds in red yeast

Influence of Commercial Protease and Drying Process on Antioxidant and Physicochemical Properties of Chicken Breast Protein Hydrolysates

Different proteases can be applied to produce certain bioactive peptides. This study focused on the effects of some commercial proteases and drying processes on the physical, chemical, and biological properties of chicken breast hydrolysates (CBH). Chicken breast hydrolyzed with Alcalase&reg; presented a higher degree of hydrolysis (DH) than papain. Moreover, the treatment with Alcalase&reg;, followed by papain (A-P), was more proficient in producing antioxidant activities than a single enzyme treatment. Conditions comprising 0.63% Alcalase&reg; (w/w) at pH 8.0 and 52.5 &deg;C for 3 h, followed by 0.13% papain (w/w) at pH 6.0 and 37 &deg;C for 3 h, resulted in the highest yields of DH and peptide contents. The spray-dried microencapsulated powder improved the physicochemical properties including moisture content, color measurement, solubility, and particle morphology. In summary, the dual enzyme application involving the hydrolysis of Alcalase&reg; and papain, coupled with the spray-drying process, could be used to produced antioxidant CBH

Bioethanol Production from Cellulose-Rich Corncob Residue by the Thermotolerant Saccharomyces cerevisiae TC-5

This study aimed to select thermotolerant yeast for bioethanol production from cellulose-rich corncob (CRC) residue. An effective yeast strain was identified as Saccharomyces cerevisiae TC-5. Bioethanol production from CRC residue via separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and prehydrolysis-SSF (pre-SSF) using this strain were examined at 35–42 °C compared with the use of commercial S. cerevisiae. Temperatures up to 40 °C did not affect ethanol production by TC-5. The ethanol concentration obtained via the commercial S. cerevisiae decreased with increasing temperatures. The highest bioethanol concentrations obtained via SHF, SSF, and pre-SSF at 35–40 °C of strain TC-5 were not significantly different (20.13–21.64 g/L). The SSF process, with the highest ethanol productivity (0.291 g/L/h), was chosen to study the effect of solid loading at 40 °C. A CRC level of 12.5% (w/v) via fed-batch SSF resulted in the highest ethanol concentrations of 38.23 g/L. Thereafter, bioethanol production via fed-batch SSF with 12.5% (w/v) CRC was performed in 5-L bioreactor. The maximum ethanol concentration and ethanol productivity values were 31.96 g/L and 0.222 g/L/h, respectively. The thermotolerant S. cerevisiae TC-5 is promising yeast for bioethanol production under elevated temperatures via SSF and the use of second-generation substrates