Nutritional requirements for methyl orange decolourisation by freely suspended cells and growing cells of Lactobacillus casei TISTR 1500

Lactobacillus casei TISTR 1500 possesses cytoplasmic azoreductase and can breakdown azo bonds under microaerophilic condition. It was found previously that a growing culture is more tolerant to a high initial dye concentration than freely suspended cells supplied only with sucrose. The present study is aimed at investigating the nutritive requirements for decolourisation by the growing cells and the freely suspended cells using Plackett-Burmann experimental design. In this study, the composition of the medium was found to play an important role in methyl orange decolourisation and biomass production. Sucrose, meat extract and peptone increased methyl orange decolourisation by freely suspended cells, whereas sodium acetate exerted a negative effect on decolourisation. In addition, it was observed that the yeast and meat extracts enhanced the degradation of the dye by the growing cells. Sucrose was an important factor in biomass production by freely suspended cells and growing cells. On the other hand, dipotassium hydrogen phosphate and sodium acetate decreased the biomass production. These findings promote the understanding and knowledge about the requirements of azo dye decolourisation by Lactobacillus casei

Exopolysaccharide production by Lactobacillus confusus TISTR 1498 using coconut water as an alternative carbon source: the effect of peptone, yeast extract and beef extract

Coconut water (CW) is a by-product of food industry and has little value in Thailand. It is usually discarded as a wasteinto the environment. Consequently, we developed a value added process of exopolysaccharide (EPS) production usingLactobacillus confusus TISTR 1498 and coconut water. The effect of three expensive supplements (peptone, yeast extractand beef extract) on EPS and biomass production was investigated at 35°C for 24 h. Using a mod-MRS-CW medium, preparedby replacing the de-ionized water with 100% CW and supplemented with 20 g/l crystalline sucrose and a reduced quantity(50%) of the three expensive supplements (5 g/l of peptone, 2.5 g/l of yeast extract, and 2.5 g/l of beef extract) gave thehighest yield of EPS (12.3 g/l). By optimizing the conditions for fermentation (pH 5.5, agitation speed at 50 rpm and initialsucrose concentration of 100 g/l), EPS yield increased up to 38.2 g/l. When compared with the modified MRS medium, themedium supplemented with CW was found to be suitable for the reduction of cost spent on the organic nitrogen and growthfactors (savings close to 50%)

Isolation and characterization of thermotolerant bacterium utilizing ammonium and nitrate ions under aerobic conditions

好気条件下で、アンモニアと硝酸塩を同時に除去する耐熱性菌を分離した。本菌は30C及び50Cにおいて両窒素化合物を効率的に除した。また、それらの代謝経路を明らかにした

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

Influence of pH, sucrose concentration and agitation speed on exopolysaccharide production by Lactobacillus confusus TISTR 1498 using coconut water as a raw material substitute

Coconut water (CW) was used as a complex nitrogen source for exopolysaccharide (EPS) production by Lactobacillus confusus TISTR 1498 to reduce the cost of fermentation medium. EPS production was carried out in a bioreactor using (0.5×) modified MRS-sucrose-CW medium, in which three relatively expensive complex nitrogen sources (peptone, yeast extract and beef extract) were halved relative to those present in (1×) modified MRS-sucrose medium. Fermentation parameters (pH, sucrose concentration and agitation speed) were varied in the process of optimisation. Under an optimised condition (pH 5.5, sucrose concentration of 100 g/L and agitation rate of 50 rpm), the maximum EPS level of 38.2 g/L was produced at 35C after 30 h of cultivation. This EPS concentration (38.2 g/L) from the (0.5×) medium was higher than those produced in the (1×) modified MRS-sucrose and (1×) modified MRS-sucrose-CW media (21.3 and 31.5 g/L respectively), both having the original concentration of all three complex nitrogen sources. Thus, in a bioreactor where the pH level was properly controlled, the EPS production was greatly enhanced. Sugar concentration also played an important role in the production of EPS

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

Improving vitamin D stability and antioxidant activity in imitation mozzarella cheese by conjugated cricket protein with fructooligosaccharide

Conjugated cricket protein with fructooligosaccharide (FOS), called CPF, is a new alternative protein ingredient with great potential for food industry applications. This study aimed to investigate the effect of CPF as a partial substitute for rennet casein on the composition, appearance, color, antioxidant activities, sensory characteristics, and functional characteristics of imitated mozzarella cheese. The effect of CPF on vitamin D retention of cheese after processing and 28 subsequent days of storage was also studied. Incorporation of CPF by 10-40 g/100g resulted in significantly increased FOS as prebiotic fibers by about 0.1-4.2 g/100g in imitation mozzarella cheese, but slightly decreased the protein content and shifted color balance darker, with more yellow and red. The addition of CPF reduced hardness, cohesiveness, springiness, and stretchability (25.0-3.6 cm) but increased meltability, adhesiveness, and free oil release (2.0-9.3 cm) of cheeses. In addition, CPF enhanced vitamin D stability in the cheese matrix by about 3 times after heat treatment and 2.8 times after 28 days of storage (4 °C) when compared to the control. It is concluded that adding 10-20 g/100g CPF in imitation cheese improved vitamin D stability and provided acceptable sensory scores for consumers (like moderately, 7.1-7.3)

In Vitro Anti-Inflammatory Activity and Structural Characteristics of Polysaccharides Extracted from <i>Lobonema smithii</i> Jellyfish

Crude polysaccharides were extracted from the white jellyfish (Lobonema smithii) using water extraction and fractionated using ion-exchange chromatography to obtain three different fractions (JF1, JF2, and JF3). The chemical characteristics of four polysaccharides were investigated, along with their anti-inflammatory effect in LPS-stimulated RAW264.7 cells. All samples mainly consisted of neutral sugars with minor contents of proteins and sulphates in various proportions. Glucose, galactose, and mannose were the main constituents of the monosaccharides. The molecular weights of the crude polysaccharides and the JF1, JF2, and JF3 fractions were 865.0, 477.6, 524.1, and 293.0 kDa, respectively. All polysaccharides were able to decrease NO production, especially JF3, which showed inhibitory activity. JF3 effectively suppressed iNOS, COX-2, IL-1β, IL-6, and TNF-α expression, while IL-10 expression was induced. JF3 could inhibit phosphorylated ERK, JNK, p38, and NF-κB p65. Furthermore, flow cytometry showed the impact of JF3 on inhibiting CD11b and CD40 expression. These results suggest that JF3 could inhibit NF-κB and MAPK-related inflammatory pathways. The structural characterisation revealed that (1→3)-linked glucopyranosyl, (1→3,6)-linked galactopyranosyl, and (1→3,6)-linked glucopyranosyl residues comprised the main backbone of JF3. Therefore, L. smithii polysaccharides exhibit good anti-inflammatory activity and could thus be applied as an alternative therapeutic agent against inflammation