Production of spiculisporic acid by Talaromyces trachyspermus in fed-batch bioreactor culture

Spiculisporic acid (SA) is a fatty acid-type biosurfactant with one lactone ring and two carboxyl groups. It has been used in metal removers and cosmetics, because of its low propensity to cause irritation to the skin, its anti-bacterial properties, and high surface activity. In the present study, we report an effective method for producing SA by selecting a high-producing strain and investigating the effective medium components, conditions, and environments for its culture. Among the 11 kinds of Talaromyces species, T. trachyspermus NBRC 32238 showed the highest production of a crystalline substance, which was determined to be SA using NMR. The strain was able to produce SA under acidic conditions from hexoses, pentoses, and disaccharides, with glucose and sucrose serving as the most appropriate substrates. Investigation of nitrogen sources and trace metal ions revealed meat extract and FeCl3 as components that promoted SA production. Upon comparing the two types of cultures with glucose in a baffle flask or aeration bioreactor, SA production was found to be slightly higher in the flask than in the reactor. In the bioreactor culture, sucrose was found to be an appropriate substrate for SA production, as compared to glucose, because with sucrose, the lag time until the start of SA production was shortened. Finally, fed-batch culture with sucrose resulted in 60 g/L of SA, with a total yield of 0.22 g SA/g sucrose and a productivity of 6.6 g/L/day

Biorefinery System of Lignocellulosic Biomass Using Steam Explosion

Recently, plant biomass has been attracting attention due to global warming and the depletion of fossil fuels. Lignocellulosic biomass (i.e., wood, straw, and bagasse) is attracting attention as an abundant renewable resource that does not compete with the food resources. It is composed of cellulose, hemicellulose, and lignin and is a potential resource that can be converted into high-value-added substances, such as biofuels, raw materials for chemical products, and cellulose nanofibers. However, due to its complicated structure, an appropriate pretreatment method is required for developing its biorefinery process. Steam explosion is one of the simplest and environmentally friendly pretreatments to decompose lignin structure, which converts cellulose into low-molecular-weight lignin with high efficiency. It has received significant attention in the field of not only biofuel but also biochemical production. Steam explosion involves the hydrolysis of plant biomass under high-pressure steam and the sudden release of steam pressure induces a shear force on the plant biomass. Moreover, it is a green technology that does not use any chemicals. Thus, a steam explosion-based biorefinery system is highly effective for the utilization of lignocellulosic into useful materials, such as ethanol, methane gas, antioxidant material, epoxy resin, and cellulose nanofiber

Proccessive ß-1,4-endoglucanase of sea hare

Endo-s-1,4-glucanase AkEG21 belonging to glycosyl hydrolase family 45 (GHF45) is the most abundant cellulase in the digestive fluid of sea hare (Aplysia kurodai). The specific activity of this 21-kDa enzyme is considerably lower than those of other endo s-1,4-glucanases in the digestive fluid of A. kurodai, therefore its role in whole cellulose hydrolysis by sea hare is still uncertain. Although AkEG21 has a catalytic domain without a cellulose binding domain, it demonstrated stable binding to cellulose fibers, similar to that of fungal cellobiohydrolase (CBH) 1 and CBH 2, which is strongly inhibited by cellohexaose, suggesting the involvement of the catalytic site in cellulose binding. Cellulose-bound AkEG21 hydrolyzed cellulose to cellobiose, cellotriose and cellotetraose, but could not digest an external substrate, azo-carboxymethyl cellulose. Cellulose hydrolysis was considerably stimulated by the synergistic action of cellulose-bound AkEG21 and AkEG45, another s-1,4-endoglucanase present in the digestive fluid of sea hare; however no synergy in carboxymethylcellulose hydrolysis was observed. When AkEG21 was removed from the digestive fluid by immunoprecipitation, the cellulose hydrolyzing activity of the fluid was significantly reduced, indicating a critical role of AkEG21 in cellulose hydrolysis by A. kurodai. These findings suggest that AkEG21 is a processive endoglucanase functionally equivalent to the CBH, which provides a CBH-independent mechanism for the mollusk to digest seaweed cellulose to glucose

Efficient Extraction of Starch from Microalgae Using Ultrasonic Homogenizer and Its Conversion into Ethanol by Simultaneous Saccharification and Fermentation

To utilize starch and protein contained in microalgae as carbon and nitrogen sources for ethanol production, an extrac- tion method, i.e. ultrasonic treatment using a homogenizer, and simultaneous saccharification and fermentation (SSF) of extracted microalgae solution were studied using Chlamydomonas fasciata Ettl 437. 30 min of ultrasonic treatment gave the maximum extraction ratio of starch contained in microalgae, i.e. 93.8%, that corresponded to 0.408 g-starch/g-dry microalgae. SSF of the extracted solution obtained from ultrasonic treated microalgae at 30 min by glutase-AN and Saccahromyces cerevisiae AM12 provided 0.194 and 0.168 g-ethanol/g-dry microalgae with and without yeast extract, respectively, corresponding to 79.5 and 68.8% of theoretical ethanol yield

Acceleration of Hericium erinaceum mycelial growth in submerged culture using yogurt whey as an alternative nitrogen source

The effects of various carbon sources and their initial concentrations on mycelia production by Hericium erinaceum were investigated by determining the dry cell weight (DCW) and β-glucan content of mycelia in submerged culture. Glucose and xylose were superior carbon sources for promoting mycelial growth re-sulting in mycelial concentrations of 3.99 g/L and 4.01 g/L, respectively; glucose was the best carbon source in terms of productivity (0.44 g/L/day). Experiments were also performed using yogurt whey as an alternative nitrogen source for submerged cultivation of H. erinaceum mycelia, and DCW and β-glucan content were compared with those with chemical nutrient medium. When whey was used as a nitrogen source, DCW and total amount of β-glucan were 2.3- and 2.8-fold higher, respectively, than that with chemical nutrient medium. Thus, whey appears to be an alternative nitrogen source for promoting H. erinaceum mycelial growth

Cellulose-binding activity of a 21-kDa endo-ß-1,4-glucanase lacking cellulose-binding domain and its synergy with other cellulases in the digestive fluid of Aplysia kurodai.

Endo-ß-1,4-glucanase AkEG21 belonging to glycosyl hydrolase family 45 (GHF45) is the most abundant cellulase in the digestive fluid of sea hare (Aplysia kurodai). The specific activity of this 21-kDa enzyme is considerably lower than those of other endo ß-1,4-glucanases in the digestive fluid of A. kurodai, therefore its role in whole cellulose hydrolysis by sea hare is still uncertain. Although AkEG21 has a catalytic domain without a cellulose binding domain, it demonstrated stable binding to cellulose fibers, similar to that of fungal cellobiohydrolase (CBH) 1 and CBH 2, which is strongly inhibited by cellohexaose, suggesting the involvement of the catalytic site in cellulose binding. Cellulose-bound AkEG21 hydrolyzed cellulose to cellobiose, cellotriose and cellotetraose, but could not digest an external substrate, azo-carboxymethyl cellulose. Cellulose hydrolysis was considerably stimulated by the synergistic action of cellulose-bound AkEG21 and AkEG45, another ß-1,4-endoglucanase present in the digestive fluid of sea hare; however no synergy in carboxymethylcellulose hydrolysis was observed. When AkEG21 was removed from the digestive fluid by immunoprecipitation, the cellulose hydrolyzing activity of the fluid was significantly reduced, indicating a critical role of AkEG21 in cellulose hydrolysis by A. kurodai. These findings suggest that AkEG21 is a processive endoglucanase functionally equivalent to the CBH, which provides a CBH-independent mechanism for the mollusk to digest seaweed cellulose to glucose

Steam Explosion Pretreatment: Biomass Waste Utilization for Methane Production

Lignocellulosic biomass as a second-generation biofuel resource such as waste from agricultural, forester industry, and unutilized wood and non-wood biomass was widely reported to use it as feedstock for methane production. As the carbon-neutral resources, biomass waste conversion for biofuel is in line with the SDGs 7 and 15 goal that can meet the needs and qualify to the standard of sustainable consumption and production pattern, and increasing the renewable energy. The wood and non-wood unutilized biomass and biomass waste are commonly faced with the recalcitrant character of the lignocellulose complex (LCC) which impacted the digestion process of the methane fermentation. Steam explosion pretreatment was enhanced the methane production by breaking the LCC into cellulose, hemicellulose, and lignin-derived product generated from the pretreatment process. Those steam-exploded products were reported effective in the conversion process into methane. The combination of steam explosion pretreatment which is an environmentally friendly pretreatment, and the use of carbon-neutral resources will provide the green biofuel which helps decrease the greenhouse gasses from the biomass waste dumping process and convert it into sustainable biofuel i.e. methane. This chapter will describe the steam explosion system development on the utilization of biomass for methane production, and the action of methane production enhancement

Efficacy and Blood Plasmalogen Changes by Oral Administration of Plasmalogen in Patients with Mild Alzheimer's Disease and Mild Cognitive Impairment: A Multicenter, Randomized, Double-blind, Placebo-controlled Trial

Background: Plasmalogens (Pls) reportedly decreased in postmortem brain and in the blood of patients with Alzheimer's disease (AD). Recently we showed that intraperitoneal administration of Pls improved cognitive function in experimental animals. In the present trial, we tested the efficacy of oral administration of scallop-derived purified Pls with respect to cognitive function and blood Pls changes in patients with mild AD and mild cognitive impairment (MCI). Methods: The study was a multicenter, randomized, double-blind, placebo-controlled trial of 24 weeks. Participants were 328 patients aged 60 to 85 years who had 20 to 27 points in Mini Mental State Examination-Japanese (MMSE-J) score and five or less points in Geriatric Depression Scale-Short Version-Japanese (GDS-S-J). They were randomized to receive either 1 mg/day of Pls purified from scallop or placebo. The patients and study physicians were masked to the assignment. The primary outcome was MMSE-J. The secondary outcomes included Wechsler Memory Scale-Revised (WMS-R), GDS-S-J and concentration of phosphatidyl ethanolamine plasmalogens (PlsPE) in erythrocyte membrane and plasma. This trial is registered with the University Hospital Medical Information Network, number UMIN000014945. Findings: Of 328 patients enrolled, 276 patients completed the trial (140 in the treatment group and 136 in the placebo group). In an intention-to-treat analysis including both mild AD (20 ≤ MMSE-J ≤ 23) and MCI (24 ≤ MMSE-J ≤ 27), no significant difference was shown between the treatment and placebo groups in the primary and secondary outcomes, with no severe adverse events in either group. In mild AD patients, WMS-R improved significantly in the treatment group, and the between group difference was nearly significant (P = 0.067). In a subgroup analysis of mild AD patients, WMS-R significantly improved among females and those aged below 77 years in the treatment group, and the between-group differences were statistically significant in females (P = 0.017) and in those aged below 77 years (P = 0.029). Patients with mild AD showed a significantly greater decrease in plasma PlsPE in the placebo group than in the treatment group. Interpretation: Oral administration of scallop-derived purified Pls may improve cognitive functions of mild AD. Funding: The Japanese Plasmalogen Society