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Heparosan, an unsulfated polysaccharide, plays a pivotal role as a primary precursor in the biosynthesis of heparin-an influential anticoagulant with diverse therapeutic applications. To enhance heparosan production, the utilization of metabolic engineering in nonpathogenic microbial strains is emerging as a secure and promising strategy. In the investigation of heparosan production by recombinant Bacillus megaterium, a kinetic modeling approach was employed to explore the impact of initial substrate concentration and the supplementation of precursor sugars. The adapted logistic model was utilized to thoroughly analyze three vital parameters: the B. megaterium growth dynamics, sucrose utilization, and heparosan formation. It was noted that at an initial sucrose concentration of 30 g L-1 (S1), it caused an inhibitory effect on both cell growth and substrate utilization. Intriguingly, the inclusion of N-acetylglucosamine (S2) resulted in a significant 1.6-fold enhancement in heparosan concentration. In addressing the complexities of the dual substrate system involving S1 and S2, a multi-substrate kinetic models, specifically the double Andrew's model was employed. This approach not only delved into the intricacies of dual substrate kinetics but also effectively described the relationships among the primary state variables. Consequently, these models not only provide a nuanced understanding of the system's behavior but also serve as a roadmap for optimizing the design and management of the heparosan production method.
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Lactobacillus rhamnosus (L. rhamnosus) is a commensal bacterium with health-promoting properties and with a wide range of applications within the food industry. To improve and optimize the control of L. rhamnosus biomass production in batch and fed-batch bioprocesses, this study proposes the application of artificial neural network (ANN) modelling to improve process control and monitoring, with potential future implementation as a basis for a digital twin. Three ANNs were developed using historical data from ten bioprocesses. These ANNs were designed to predict the biomass in batch bioprocesses with different media compositions, predict biomass in fed-batch bioprocesses, and predict the growth rate in fed-batch bioprocesses. The immunomodulatory effect of the L. rhamnosus samples was examined and found to elicit an anti-inflammatory response as evidenced by the inhibition of IL-6 and TNF-α secretion. Overall, the findings of this study reinforce the potential of ANN modelling for bioprocess optimization aimed at improved control for maximising the volumetric productivity of L. rhamnosus as an immunomodulatory agent with applications in the functional food industry.
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Every year, the EU emits 13.4 Mt of CO2 solely from plastic production, with 99% of all plastics being produced from fossil fuel sources, while those that are produced from renewable sources use food products as feedstocks. In 2019, 29 Mt of plastic waste was collected in Europe. It is estimated that 32% was recycled, 43% was incinerated and 25% was sent to landfill. It has been estimated that life-sciences (biology, medicine, etc.) alone create plastic waste of approximately 5.5 Mt/yr, the majority being disposed of by incineration. The vast majority of this plastic waste is made from fossil fuel sources, though there is a growing interest in the possible use of bioplastics as a viable alternative for single-use lab consumables, such as petri dishes, pipette tips, etc. However, to-date only limited bioplastic replacement examples exist. In this review, common polymers used for labware are discussed, along with examining the possibility of replacing these materials with bioplastics, specifically polylactic acid (PLA). The material properties of PLA are described, along with possible functional improvements dure to additives. Finally, the standards and benchmarks needed for assessing bioplastics produced for labware components are reviewed.
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Fermentative poly-3-hydroxybutyrate (PHB) production is mainly limited by the cost of raw material. In this present study, low-cost feedstock viz., millet bran residue (MBRH) and rapeseed meal hydrolysates were successfully utilized for PHB production. Metabolic engineering of Bacillus megaterium by co-expression of both precursor (phbRBC) and NADPH cofactor regeneration (zwf) genes resulted in 2.67-fold enhancement in PHB accumulation compared to wild strain. Modified logistic model characterized B.megaterium growth and PHB production effectively. The kinetic analysis proved that maximum cell concentration (15.01 g.L-1) and growth-associated constant (0.22 g.g-1) were found to be higher for initial MBRH concentration (S0 = 20 g.L-1). PHB production kinetics elucidated its expression in B.megaterium was growth-associated. PHB synthesized by B.megaterium was characterized using FTIR, NMR, XRD, DSC/TGA, FESEM and the physio-chemical properties enumerated its as a potential biodegradable plastic for industrial application.
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Bacillus megaterium , Brassica napus , Ácido 3-Hidroxibutírico , Hidroxibutiratos , Cinética , Mijos , PoliésteresRESUMEN
D-lactic acid (DLA) serves as a key monomer enhancing both the mechanical and thermal properties of Poly(lactic) acid films and coatings, extensively used in the food packaging industry. Economically viable production of optically pure DLA by Lactobacillus delbrueckii NBRC3202 was achieved using a low-cost carbon source, Kodo millet bran residue hydrolysate (KMBRH) and nitrogen source (casein enzyme hydrolysate (CEH) resulting in a high DLA yield of 0.99 g g-1 and KMBRH conversion to final product (95.3%). The optimum values for kinetic parameters viz., specific growth rate (0.11 h-1), yield coefficient of biomass on KMBRH (0.10 g g-1) and DLA productivity (0.45 g L-1 h-1) were achieved at 5 g L-1 of CEH dosage under controlled pH environment. A comparative study and kinetic analysis of different neutralizing agents (NaOH, NH3, CaCO3 and NaHCO3) under pH controlled environment for KMBRH based DLA production was addressed effectively through bioreactor scale experiments. Maximum cell concentration (1.29 g L-1) and DLA titer (45.08 g L-1) were observed with NH3 as a neutralizing agent. Kinetic analysis of DLA production under different neutralization agents demonstrated that the logistic derived model predicted biomass growth, KMBRH consumption and DLA production efficiently (R 2 > 0.92).
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A low-cost Kodo millet bran residue was utilized as feedstock for the production of D (-) lactic acid (DLA) using Lactobacillus delbrueckii NBRC3202 under anaerobic condition. Data culled from a series of batch fermentation processes with different initial Kodo millet bran residue hydrolysate (KMBRH) and DLA concentrations were used for kinetic model development. Both simulated and experimental data were in good agreement for cell growth, KMBRH utilization, and DLA formation. The values of kinetic constants specific growth rate, (µm = 0.17 h-1); growth (αP = 0.96 g.g-1) and non-growth (ßP = 1.19 g.g-1.h-1) associated constant for DLA production and the maximum specific KMBRH utilization rate, (qG, max = 1.18 g.g-1.h-1) were in good agreement with the literature reports. Kinetic analysis elucidated that L. delbrueckii growth was predominantly influenced by KMBRH limitation and highly sensitive to DLA inhibition. Fed-batch fermentation studies demonstrated the existence of substrate and product inhibition paving the scope for process intensification.
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Fermentación , Ácido Láctico/metabolismo , Paspalum/química , Semillas/química , Hidrólisis , Cinética , Ácido Láctico/química , Lactobacillus delbrueckii/metabolismoRESUMEN
Hyaluronic acid (HA) production using a dairy industrial waste is a more cost-efficient strategy than using an expensive synthetic medium. In this study, we investigated the production of HA using Streptococcus thermophilus under shake flask conditions using dairy industrial waste as nutritional supplements, namely whey permeate (WP) and whey protein hydrolysate (WPH). Preliminary screening using Plackett-Burman design exhibited WP, WPH, initial pH, and inoculum size as significant factors influencing HA titer. Response surface methodology design of four factors was formulated at three levels for enhanced production of HA. Shake flask HA fermentation by S. thermophilus was performed under global optimized process conditions and the optimal HA titer (342.93 mg L(-1)) corroborates with Box-Behnken design prediction. The molecular weight of HA was elucidated as 9.22-9.46 kDa. The ultralow-molecular weight HA reported in this study has a potential role in drug and gene delivery applications.