Bacterial cellulose (BC) is a valuable biopolymer typically observed in Kombucha with many potential food applications. Many studies highlight yeast’s roles in providing reducing sugars, used by the bacteria to grow and produce BC. However, whether yeast could enhance the BC yields remains unclear. This study investigates the effect of yeast Dekkera bruxellensis on bacteria Komagataeibacter intermedius growth and BC production in molasses medium. The results showed that the co-culture stimulated K. intermedius by ~2 log CFU/mL, which could be attributed to enhanced reducing sugar utilization. However, BC yields decreased by ~24%, suggesting a negative impact of D. bruxellensis on BC production. In contrast to other studies, regardless of D. bruxellensis, K. intermedius increased the pH to ~9.0, favoring the BC production. Furthermore, pH increase was slower in co-culture as compared to single culture cultivation, which could be the reason for lower BC yields. This study indicates that co-culture could promote synergistic growth but results in the BC yield reduction. This knowledge can help design a more controlled fermentation process for optimum bacterial growth and, ultimately, BC production.

Bacterial Cellulose (BC) is a biopolymer with numerous applications. The growth of BC-producing bacteria, Komagataeibacter intermedius, could be stimulated by Dekkera bruxellensis, however, the effect on BC yield needs further investigation. This study investigates BC production and biochemical changes in the K. intermedius-D. bruxellensis co-culture system. D. bruxellensis was introduced at various concentrations (10³ and 10⁶ CFU/mL) and inoculation times (days 0 and 3). BC yield was ~24% lower when D. bruxellensis was added at 10³ CFU/mL compared to K. intermedius alone (0.63 ± 0.11 g/L). The lowest BC yield was observed when 10³ CFU/mL yeast was added on day 0, which could be compromised by higher gluconic acid production (10.08 g/L). In contrast, BC yields increased by ~88% when 10⁶ CFU/mL D. bruxellensis was added, regardless of inoculation time. High BC yield might correlate with faster sugar consumption or increased ethanol production when 10⁶ CFU/mL D. bruxellensis was added on day 0. These results suggest that cell concentration and inoculation time have crucial impacts on species interactions in the co-culture system and product yield.

Composting is an organic waste management option, where suitable microorganisms are used to accelerate the rate and the decomposition process and improve the final compost quality. In this study, a commercial bio-activator EM4 (EM) and a traditional bio-activator prepared according to the Takakura method (Tak) were investigated. The bio-activators were mixed with a fermenting bed (fb) material consisting of rice husk and rice bran mixed in a ratio of 1:1. The inoculated fb was then used in concentrations of 0%, 20%, and 40% in a composting process of food waste. The composting process was monitored daily for 48 days, and the quality of the final compost based on its physical and chemical characteristics was measured and compared. The result revealed that all samples containing 40% fb material with both Tak and EM bio- activator contained lower moisture content in the final compost compared to samples with 20% fb material. The C/N ratio of the samples with 20% fb material for all samples decreased to 20:1, while 40% fb material increased above 20:1, compared to its initial level. Furthermore, the nitrogen level for all samples with 20% fb material increased while samples with 40% fb material decreased from the initial level. The phosphorus and potassium content also increased for all samples with both 20% and 40% fb material from the initial level. Additionally, no significant difference could be found for the final compost quality between the two bio-activators.

The large quantities of waste sludge produced by the pulp and paper industry present significant environmental challenges. In order to minimize the amounts of waste, the pulp sludge should be utilized for productive applications. In order to find feasible solutions, the sludge need to be characterized. In this study, the potential of using acid pretreatment and ashing method to determine the chemical compositions of the sludge is investigated. This study shows that acid pretreatment could be used to dissolve and determine the composition of CaCO₃ in the pulp sludge. CaCO₃ removal also facilitates the measurement of fiber and ash (clay) contents by using the ashing method. The optimum acid concentration used to completely dissolve CaCO₃ was determined using a titration method. Using this method, the measurement of the chemical composition of the sludge sample revealed that it consisted primarily of CaCO₃ (55% w/w), clay (25%, w/w), and fibers (18%, w/w). Based on these chemical compositions, potential utilization for the sludge could be determined.

Smoking is a common practice of recreational drug use. Smoking has been known for its adverse effects on both physical and mental health. Smoking also leads to nicotine dependence, which produces various deleterious effects on smokers. The latest data from WHO revealed that smoking is the leading cause of death due to non-communicable diseases. Smoking has unalived 8 million people worldwide, and this number keeps increasing, especially in low- to middle-income middle-income countries. Treatment for nicotine dependence has been widely developed and shown promising efficacy in inducing abstinence; however, this utilization remains low due to limited treatment options. Hence, providing a new alternative for smoking cessation to give a new treatment option could help achieve cessation success. This study aims to determine the lead compound from natural alkaloids that could act as an antagonist towards nicotinic acetylcholine receptors (nAChrs) using an in silico approach. The target receptor nicotinic acetylcholine receptor (nAChRs) subtype α4β2 is one of the target receptors responsible for the occurrence of nicotine dependence in humans. The experiment includes a virtual screening of potential nAChRs subtype α4β2 antagonist with Quantitative Structure-Activity Relationship (QSAR) analysis, molecular docking using Patchdock, VisualizationVisualization, and toxicity analysis. Six of 43 alkaloids showed good potential as antagonists based on the complementary geometry scores and binding potential.