Industrial Biotechnology

Mother’s milk provides numerous important and beneficial properties. In addition to its rich immunological factors and its role as a natural vaccine, it also contains a diverse microbiome that contributes to the gastrointestinal colonization of children. This review focuses on the role of lactic acid bacteria (LAB) found in breast milk, which play a key part in shaping the infant’s microbiota. LAB are also gaining attention for their potential use as probiotics, known for their ability to support and improve health without adverse side effects. Moreover, microbial metabolites present in breast milk have become the subject of growing interest, particularly regarding their influence on the development of the infant’s neurological and immune systems. Because LAB are classified as Generally Recognized As Safe, they hold promise for the development of safer vaccines, offering a gentler alternative to traditional pathogen-based vaccines, which are more difficult to administer and can irritate the skin. This review examines significant studies that highlight the important functions of LAB in breast milk and discusses their potential implications for infant and maternal health.

The purpose of this study is to optimize technological factors controlling pretreatments of banana puree products derived from Vietnamese banana for extraction of high-quality banana juice. These pretreatments included freezing, followed by pectinase-based hydrolysis with controlling parameters of freezing temperature, hydrolysis temperature, and hydrolysis time. A small central composite design (SCCD) was chosen for investigation and optimization of the effects of freezing temperature (−30°C to −20°C), enzyme hydrolysis temperature (45–55°C), and time (150–210 minutes) on recovery efficiency (%), clarity (%T), and sensory quality (score) of puree banana juice. Data revealed that the three targeted variables displayed significant influences on all responses. Moreover, mathematical quadratic models of juice recovery efficiency, clarity, and sensory quality yielded regression coefficients of 0.9963, 0.9865, and 0.9902, respectively, demonstrating a high fitness of the predicted and experimental data from different combinations of freezing temperature, hydrolysis temperature, and hydrolysis time. The process parameters were numerically optimized using Design-Expert software for maximization of juice recovery efficiency, clarity, and sensory quality. The optimal technological parameters were freezing temperature of −25°C, hydrolysis temperature of 50.21°C, and hydrolysis time of 180.42 minutes, under which juice recovery efficiency, clarity, and sensory quality were predicted of 55.16%, 98.47%T, and 18.9 points (total soluble solids content of 28.9 °Brix). Banana juice recovery efficiency, clarity, and sensory quality measured from confirmatory experiments were 54.78 ± 0.85%, 98.11 ± 0.75%T, and 18.65 ± 0.27 points, which differ from modeled values of −1.32% to −0.37%, demonstrating the reliability and accuracy of the established models. The quality of banana juice obtained in this study is superior to that reported in the literature, particularly sensory quality.

The rapid spread of the invasive aquatic plant Eichhornia crassipes (water hyacinth [WH]) poses serious ecological and environmental challenges. This study explores the potential valorization of WH biomass by using the fungus Aspergillus niger to produce filter paperase (FPase). A classical screening approach was followed by optimization using response surface methodology with a central composite design (CCD) via Stat-Ease 360 software. Incubation time, pH, and lactose concentration were selected as key parameters for optimization. Maximum FPase activity (4.10 U/mL) was achieved under conditions of 6 days incubation, pH 5.5, and 1.25% (w/v) lactose. To enhance enzyme accessibility, the biomass was pretreated using steam-assisted NaOH, resulting in substantial compositional changes: cellulose content increased by 41.67%, while lignin and hemicellulose decreased by 58.71% and 11.74%, respectively. The highest fermentable sugar yield (0.294 ± 0.04 g/g) was obtained after 96 hours of enzymatic hydrolysis using 30 FPU/100 mL of FPase and 3% (w/v) substrate loading. These results highlight the dual benefit of converting an environmental nuisance into a valuable resource. WH-derived FPase shows significant promise for applications in bioethanol production, biomass valorization, and integrated biorefinery systems. Moreover, this work suggests a sustainable and eco-friendly approach to managing invasive aquatic weeds through microbial bioconversion.

To enhance the activity of the thermophilic consortium, different inoculum sources were selected to study their effect on the thermophilic consortium for enhanced biogas production using water hyacinth (WH) as a feedstock. WH was inoculated with a novel thermophilic consortium enriched with a pinch of poultry droppings, horse dung, yak dung, sewage sludge, sewage effluent, and a blend of all waste samples individually, along with a control, in a batch digester. Six sets of experiments, including a control, were performed with a total solid content of 5% (w/v) inoculated with a 10% (w/v) thermophilic consortium enriched with a pinch of each inoculum source. In all the experiments, the 52°C temperature was maintained with a batch time of 26 days. The biogas yield was found to be 356.8 L/kg volatile solid (VS) (control), 469.2 L/kg VS (sewage sludge), 513.1 L/kg VS (poultry droppings), 472.4 L/kg VS (yak dung), 428.5 L/kg VS (sewage effluent), and 461.1 L/kg VS (mixture of all the samples), respectively. All the digesters containing enriched consortium showed improved biogas production with 16–30% higher yield than the control. The first-order and modified Gompertz models were fitted for the kinetic analysis. Different kinetic parameters, including the maximum biogas production rate (Rm), lag phase (λ) duration, biogas yield potential (P), and specific microbial growth rate, were estimated in each case. It was found that the biogas yield was highest in the digester containing the consortium enriched with poultry droppings.

This study investigates the clarification of Citrus limetta (sweet lime) juice using a packed bed system incorporating polyvinyl alcohol (PVA)-alginate immobilized pectinase. Free pectinase, though widely used in juice clarification, suffers from drawbacks such as instability, loss of activity, and lack of reusability. To overcome these limitations, pectinase was immobilized via entrapment in a PVA-alginate matrix, forming stable enzyme beads. The immobilized enzyme was characterized for its optimal pH, temperature, incubation time, and reusability. The results indicated that the immobilized pectinase exhibited maximum activity at pH 5 and 40°C, with optimal incubation at 60 minutes. The reusability study showed significant 58% enzymatic activity retention for up to three cycles. Application of immobilized pectinase in a packed bed column demonstrated effective juice clarification of 37%, with a marked reduction in turbidity. The developed system provides a cost-effective and efficient approach for industrial fruit juice processing, enhancing clarity and stability while enabling enzyme reusability.

Strong mineral acids such as sulfuric acid are still mainly used to break down carbohydrates in processes that prepare plant-based waste for further use. However, researchers are increasingly studying the use of organic acids as alternatives. This study aimed to obtain organic compounds by fermenting a hemicellulosic extract rich in simple sugars from the organic acid pretreatment of brewer’ spent grain. Hydrolysis tests using 4.5% oxalic acid for 24 minutes at 125.6°C dissolved over 99% of the hemicellulose, producing 14.9 g/L of xylose and 4.9 g/L of glucose. The production of inhibitory compounds was relatively low (0.05 g/L and 0.12 g/L of 5-hydroxymethylfurfural and furfural, respectively), which is beneficial for the yeast’s performance during the next step. The extract was then fermented by three strains of Saccharomyces cerevisiae: one industrial strain (PE-2) and two genetically modified strains (MP-P5 and JDY-01). Despite the hydrolysate containing around 45 g/L of oxalic acid, which significantly inhibited yeast activity in producing ethanol, for example, the three strains still produced several important volatile organic compounds, including 2-phenylethanol, known for its antimicrobial properties, and 4-hydroxy-2-methylacetophenone, a phenolic compound with antioxidant and antiseptic properties.

There is increasing demand for microbial lipids as a sustainable alternative to mitigate the detrimental environmental and societal impacts associated with the production of palm oil, including tropical deforestation, significant contributions to global warming, and extensive land and water use. Microbial lipid production has the potential to address these concerns and meet the growing demand for palm oil through strain engineering and innovative fermentation and downstream process development. However, the current cost to produce microbial oils is not competitive with traditional sources of palm oil, and improvements in fermentation titer, rate, and yield are needed. We report here the application of Adaptive Laboratory Evolution to improve lipid production by the oleaginous yeast Rhodosporidium toruloides, multi-omic characterization of the genome-wide metabolic rewiring resulting from its evolutionary adaptation, and scale-up of a high-cell density fed-batch fermentation process to 50 m³ commercial scale. The methods, strains, and process improvements described here represent significant steps toward commercialization of a fermentation-based palm oil substitute.