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Bacterial nanocellulose (BNC) is a unique biopolymer with remarkable purity and material properties that distinguish it from plant-derived cellulose by its absence of lignin and hemicellulose. Recent research has focused on using organic waste materials as alternative substrates to reduce the cost of BNC production. This study examines the efficacy of Siwalan neer and sugarcane molasses as novel media for cultivating Komagataeibacter xylinus by comparing their performance with that of Hestrin and Schramm (HS) medium. The BNC harvested from these alternative media was rigorously characterized using scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Thermogravimetric Analysis (TGA) to evaluate its structural and thermal properties. Notably, the use of Siwalan neer and sugarcane molasses as growth substrates enabled K. xylinus to produce BNC at a yield of 3.83 g/L, significantly exceeding the yield from the HS medium, which was 1.46 g/L. These findings highlight the potential of leveraging alternative substrates to enhance BNC production yield, cost-effectiveness, and environmental sustainability.

Abstract Microbial flocculants are macromolecular substances produced by microorganisms. Due to its non-toxic, harmless, and biodegradable advantages, microbial flocculants have been widely used in various industrial fields, such as wastewater treatment, microalgae harvest, activated sludge dewatering, heavy metal ion adsorption, and nanoparticle synthesis, especially in the post-treatment process of fermentation with high safety requirement. However, compared with the traditional inorganic flocculants and organic polymeric flocculants, the high production cost is the main bottleneck that restricts the large-scale production and application of microbial flocculants. To reduce the production cost of microbial flocculant, a series of efforts have been carried out and some exciting research progresses have been achieved. This paper summarized the research advances in the last decade, including the screening of high-yield strains and the construction of genetically engineered strains, search of cheap alternative medium, the extraction and preservation methods, microbial flocculants production as an incidental product of other biological processes, combined use of traditional flocculant and microbial flocculant, and the production of microbial flocculant promoted by inducer. Moreover, this paper prospects the future research directions to further reduce the production cost of microbial flocculants, thereby promoting the industrial production and large-scale application of microbial flocculants.

BACKGROUND: This study investigated the feasibility of producing pigments from Scenedesmus dimorphus using different low‐cost synthetic and alternative media. Thus the influence of nitrogen and phosphorus deficiency, different nitrogen sources and alternative culture media (wheat bran, garlic powder, wheat bran supplemented with garlic powder) on pigment and biomass production was evaluated. RESULTS: Among the three sources of nitrogen studied (ammonium sulfate, urea and sodium nitrate), urea was the cheapest efficient alternative source of nitrogen for pigment production, especially total chlorophylls (67.38 μg L−1 d−1), by this strain, without strongly affecting biomass yield. Phosphorus deficiency had no negative effect on biomass production, but improved the production of zeaxanthin and chlorophyll b by13.1% and 26.8%, respectively, compared to control. Compared to BG‐11 medium, the alternative garlic powder medium increased the biomass yield of S. dimorphus by 5.2 times, improved the productivity of xanthophylls and contributed to the accumulation of β‐carotene. Wheat bran medium was found to be efficient as a zero‐cost culture medium for the production of pigments, where S. dimorphus accumulated twice the total pigment concentration of the control, with high β‐carotene productivity (38.58 ± 11.94 μg L−1 d−1). The addition of garlic powder to wheat bran increased the biomass (3.14 g L−1) and pigment productivity (216.86 ± 2.06 μg L−1 d−1) by 28.5 and 1.4 times, respectively, but inhibited zeaxanthin biosynthesis. This alternative medium reduced biomass and pigment production costs by 99.80% and 96.21%, respectively. CONCLUSION: Wheat bran supplemented with garlic powder showed good application potential for the industrial production of biomass and pigments from S. dimorphus in open cultivation systems where garlic powder might be used simultaneously for biomass and pigment accumulation, and for biological contamination control. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Euglena gracilis (E. gracilis) accumulates paramylon, an immune-functional beta-glucan that can be used as a functional food. Paramylon production is strongly affected by the organic carbon source and the initial pH conditions. Food processing byproducts have attracted attention for microalgal cultivation because of their low cost and abundance of nutrients, including carbon and nitrogen. We investigated the optimal carbon source and its concentration for efficient paramylon production. A spent tomato byproduct (STB) generated from a tomato processing plant was applied for biomass and paramylon production from E. gracilis with respect to the initial pH condition. The highest paramylon concentration (1.2 g L−1) and content (58.2%) were observed with 15 g L−1 glucose. The biomass production increased when STB was used as compared with that when a synthetic medium was used (1.6-fold higher at pH 3 and 2-fold higher at pH 8). The optimal initial pH was determined according to the maximum production of biomass and paramylon. Upcycling the food processing byproduct, STB, can contribute not only to cost reduction of the biorefinery process using E. gracilis but also to environmental remediation by removing organic carbon and nitrogen from the byproducts. [ABSTRACT FROM AUTHOR]

The availability of non-synthetic media from natural ingredients is needed to answer the needs in laboratories where the price of nutrient media is quite expensive and there are limited supplies of material ware houses. Cowpea (Vigna unguiculata L.) and pigeonpea (Cajanus cajan L.) are the local foods of people of NTT (East Nusa Tenggara) which have a high enough nutritional content which has the potential to be developed into cheap, easy and simple non-synthetic media in making. The purpose of this study was to determine whether the agar media contained nutrient from cowpea and pigeonpea water can be used as a alternative for nutrient agar for the growth of Escherchia coli and Staphylococcus aureus bacteria. This research is a true experiment with posttest-only control design. The growth rate of S. aureus bacteria on pigeonpea medium, cowpea medium, nutrient agar medium, were 164 CFU/mL (SD=3,13), 161 CFU/mL (SD=3,02) and 164 CFU/mL (SD=3,21), respectively. The average growth of E. coli on cowpea medium, pigeonpea medium, and nutrient agar control medium were 163 CFU/mL (SD=2,79), 167 CFU/mL (SD-2,63) and 164 CFU/mL (SD=2,75) respectively. Test results ANOVA between pigeonpea medium, cowpea medium and nutrient medium in order to obtain p value = 0.145 (p> 0.05) for the growth of E. coli bacteria and p value = 0.393 (p> 0.05) for growth S. aureus. It was concluded that there was no difference between the number of bacterial colonies of E. coli and S. aureus on three medium. The pigeonpea medium and cowpea can be used to grow and alternative nutrient agar in order to grow bacteria E. coli and S. aureus.

Microbial flocculants are macromolecular substances produced by microorganisms. Due to its non-toxic, harmless, and biodegradable advantages, microbial flocculants have been widely used in various industrial fields, such as wastewater treatment, microalgae harvest, activated sludge dewatering, heavy metal ion adsorption, and nanoparticle synthesis, especially in the post-treatment process of fermentation with high safety requirement. However, compared with the traditional inorganic flocculants and organic polymeric flocculants, the high production cost is the main bottleneck that restricts the large-scale production and application of microbial flocculants. To reduce the production cost of microbial flocculant, a series of efforts have been carried out and some exciting research progresses have been achieved. This paper summarized the research advances in the last decade, including the screening of high-yield strains and the construction of genetically engineered strains, search of cheap alternative medium, the extraction and preservation methods, microbial flocculants production as an incidental product of other biological processes, combined use of traditional flocculant and microbial flocculant, and the production of microbial flocculant promoted by inducer. Moreover, this paper prospects the future research directions to further reduce the production cost of microbial flocculants, thereby promoting the industrial production and large-scale application of microbial flocculants. [ABSTRACT FROM AUTHOR]

The aim of this study was to establish a low-cost alternative protocol for micropropagation of Solanum lycopersicum L. var. cerasiforme, popularly known as cherry tomato. In the in vitro establishment, culture media containing Laboratory Reagent-grade (LR) and commercial sucrose and varied concentrations of corn starch and agar were tested. The replacement of thermal sterilization, using autoclave, with chemical sterilization, adding sodium hypochlorite (2%) in the medium, was also evaluated. In the multiplication stage, the medium was supplemented with agar and/or corn starch and commercial sucrose. For rooting, a growth regulator-free medium with commercial sucrose supplemented with agar and/or starch was used. The microplants were then transplanted into plastic containers containing only garden substrate and subsequently acclimatized in a greenhouse. The results make it possible to conclude that the reduction of costs in the micropropagation of cherry tomato can be obtained by replacing LR sucrose with commercial sucrose, and by the use of chemical sterilization of the culture medium with sodium hypochlorite. The replacement of agar with corn starch can be done partially, in the stages of establishment and multiplication, and totally, during rooting. [ABSTRACT FROM AUTHOR]

Kombucha tea is a traditional fermented beverage of Manchurian origins which is made of sugar and tea. The fermentation involves the application of a symbiotic consortium of bacteria and yeast (SCOBY) in which their metabolites provide health benefits for the consumer and subsequently allow the product to protect itself from contamination. Additionally, kombucha tea fermentation also produces a byproduct in the form of a pellicle composed of cellulose (Bacterial Cellulose, BC). Compared to plant cellulose, BC properties are more superior, which makes it industrially important. However, BC production at industrial scale has been faced with many challenges, including low yield and high fermentation medium cost. Many researchers have focused their studies on the use of alternative low cost media, such as molasses, which is a by-product of sugar refining process. To maximize the BC production in molasses medium, it is important to select the microbial strains that can grow and produce BC at high yield in molasses. This study aimed to isolate and characterize BC-producing bacteria and a dominant yeast from kombucha culture which had been previously adapted in molasses medium. The isolation of bacteria was performed using Nutrient Agar (NA) and Hestrin and Schramm (HS) supplemented with cycloheximide, while yeast was isolated using Potato Dextrose Agar (PDA) supplemented with chloramphenicol. The most dominant colonies were isolated and then subjected to microscopic observation for morphological analysis. The pure bacteria and yeast isolates were then identified by sequencing the 16S rRNA gene and D1/D2 region of the 26S rRNA, respectively. The bacteria isolates obtained were all from closely related genera: Komagataeibacter sp. DS1MA.62A, Komagataeibacter xylinus, Komagataeibacter saccharivorans, Komagataeibacter xylinus and Gluconacetobacter saccharivorans. The single isolated yeast was identified as Brettanomyces bruxellensis. This study helps to elucidate the BC-producing species which thrive in molasses medium for potential use in the BC production using molasses as alternative cheap carbon source. Also, the study revealed that the co-culture of Komagataeibacter sp. DS1MA.62A and B. bruxellensis could produce BC from molasses supplemented with caffeine and acetate buffer at an average yield of 27.7±1.83 g/L. [ABSTRACT FROM AUTHOR]

Euglena gracilis (E. gracilis) accumulates paramylon, an immune-functional beta-glucan that can be used as a functional food. Paramylon production is strongly affected by the organic carbon source and the initial pH conditions. Food processing byproducts have attracted attention for microalgal cultivation because of their low cost and abundance of nutrients, including carbon and nitrogen. We investigated the optimal carbon source and its concentration for efficient paramylon production. A spent tomato byproduct (STB) generated from a tomato processing plant was applied for biomass and paramylon production from E. gracilis with respect to the initial pH condition. The highest paramylon concentration (1.2 g L−1) and content (58.2%) were observed with 15 g L−1 glucose. The biomass production increased when STB was used as compared with that when a synthetic medium was used (1.6-fold higher at pH 3 and 2-fold higher at pH 8). The optimal initial pH was determined according to the maximum production of biomass and paramylon. Upcycling the food processing byproduct, STB, can contribute not only to cost reduction of the biorefinery process using E. gracilis but also to environmental remediation by removing organic carbon and nitrogen from the byproducts.

The effect of different concentrations (10, 20, 30 and 40%) of urban secondary sewage on the growth of Tetraselmis chuii (Prasinophyceae) and Dunaliella viridis (Chlorophyceae) was examined to verify the possibility of its use as an alternative culture medium for these species. Stocks and 700mL duplicate batch cultures were maintained under controlled laboratory conditions. 30% and 40% additions were the most efficient for the growth of both species. Statistical analysis of the adjusted growth (cell.mL-1) and biomass (µg chlorophyll-a.mL-1) curves performed using the Chi-square test (pFoi estudado o efeito das diferentes concentrações de esgoto urbano secundário (10%, 20%, 30% e 40%) sobre o crescimento de Tetraselmis chuii (Prasinophyceae) e Dunaliellla viridis (Chlorophyceae) para verificar a possibilidade do seu uso como meio de cultura altenativo para estas espécies. Culturas stocks duplicatas de 700mL foram mantidas sob condições de laboratório controladas. As adições de 30% e 40% foram as mais eficientes para o crescimento de ambas as espécies. Análises estatísticas para o ajuste do crescimento (cel.mL-1) e curvas de biomassa (µg clorofila-a.mL-1) em relação ao tempo de cultura desenvolvidas usando Chi-square test (p