Statistical and nature-inspired metaheuristics analysis on flexirubin production

Nowadays, demand for natural pigments has increased dramatically due to the awareness of the toxicity of some synthetic pigments. Because of the high cost of growth medium for natural pigment production, various studies have been carried out to explore medium which are less costly, such as agricultural waste. This study highlight on the application of firefly algorithm (FA) and bat algorithm (BA) in optimizing yellowish-orange pigment production (flexirubin) from the agricultural waste material. At present, response surface methodology (RSM) is the most preferred statistical method in optimizing pigment production. However, in the last two decades, nature-inspired metaheuristics approach has been used extensively in the fermentation process and have continually improve the efficiency in the optimization problem especially in pigment production. This study compared the analytics studies of RSM, FA and BA in the estimation of fermentation parameters (Lactose, Ltryptophan, and KH2PO4) in flexirubin production from Chryseobacterium artocarpi CECT8497T. All models provided similar quality predictions for the above three independent variables in term of flexirubin production with bat algorithm showing more accurate in estimation, with the coefficient value of 98.87% compare to RSM 98.20% and FA 98.38%

Characterization of bioactive colored materials produced from bacterial cellulose and bacterial pigments

A Bacterial Cellulose (BC) film was developed and characterized as a potential functional bioactive material. BC films, obtained from a microbial consortium of bacteria and yeast species, were functionalized with the bacterial pigment prodigiosin, produced by Serratia plymuthica, and flexirubin-type pigment, from Chryseobacterium shigense, which exhibit a wide range of biological properties. BC was successfully functionalized at 15% over the weight of the fiber at 40 °C during 60 min, and a color strength of 1.00 ± 0.01 was obtained for BC_prodigiosin and 0.38 ± 0.02 for BC_flexirubin-type pigment. Moreover, the BC films showed moderate hydrophilic character following alkaline treatment, which was maintained after both pigments were incorporated. The porosity and mechanical performance of the functionalized BC samples also remained unaffected. Furthermore, the BC samples functionalized with prodigiosin presented antibacterial activity and were able to inhibit the growth of pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa, with inhibition rates of 97.89 ± 0.60% and 85.12 ± 0.17%, respectively, while BC samples functionalized with flexirubin-type pigment exhibited the highest antioxidant activity, at 38.96 ± 0.49%. This research provides an eco-friendly approach to grant BC film-based material with color and advantageous bioactive properties, which can find application in several fields, especially for medical purposes.This work was funded by the Portuguese Foundation for Science and Technology (FCT), I.P./MCTES through national funds (PIDDAC), in the scope of the FibEnTech Research Unit project (UIDB/00195/2020) and of the 2C2T Research Unit Project (UIDB/00264/2020). L.F.A. Amorim also acknowledges the doctoral fellowship (PD/BD/128417/2017) from Portuguese Foundation for Science and Technology (FCT), co-financed by the European Social Fund (FSE), through the Regional Operational Program of the Center (Centro2020)

Utilization of Cassava Wastewater for Low-Cost Production of Prodigiosin via Serratia marcescens TNU01 Fermentation and Its Novel Potent α-Glucosidase Inhibitory Effect

[[abstract]]The purpose of this study was to reuse cassava wastewater (CW) for scaled-up production, via the fermentation of prodigiosin (PG), and to conduct an evaluation of its bioactivities. PG was produced at the yield of high 6150 mg/L in a 14 L-bioreactor system, when the designed novel medium (7 L), containing CW and supplemented with 0.25% casein, 0.05% MgSO4, and 0.1% K2HPO4, was fermented with Serratia marcescens TNU01 at 28 °C in 8 h. The PG produced and purified in this study was assayed for some medical effects and showed moderate antioxidant, high anti-NO (anti-nitric oxide), and potential α-glucosidase inhibitory activities. Notably, PG was first reported as a novel effective α-glucosidase inhibitor with a low IC50 value of 0.0183 µg/mL. The commercial anti-diabetic drug acarbose was tested for comparison and had a lesser effect with a high IC50 value of 328.4 µg/mL, respectively. In a docking study, the cation form of PG (cation-PG) was found to bind to the enzyme α-glucosidase by interacting with two prominent amino acids, ASP568 and PHE601, at the binding site on the target enzyme, creating six linkages and showing a better binding energy score (−14.6 kcal/mol) than acarbose (−10.5 kcal/mol). The results of this work suggest that cassava wastewater can serve as a low-cost raw material for the effective production of PG, a potential antidiabetic drug candidate.[[sponsorship]]MOST[[notice]]補正完

Bacterial synthesis of nanoparticles: A green approach

In recent decades, the attention of scientists has been drawn towards nanoparticles (NPs) of metals and metalloids. Traditional methods for the manufacturing of NPs are now being extensively studied. However, disadvantages such as the use of toxic agents and high energy consumption associated with chemical and physical processes impede their continued use in various fields. In this article, we analyse the relevance of the use of living systems and their components for the development of "green" synthesis of nano-objects with exceptional properties and a wide range of applications. The use of nano-biotechnological methods for the synthesis of nanoparticles has the potential of large-scale application and high commercial potential. Bacteria are an extremely convenient target for green nanoparticle synthesis due to their variety and ability to adapt to different environmental conditions. Synthesis of nanoparticles by microorganisms can occur both intracellularly and extracellularly. It is known that individual bacteria are able to bind and concentrate dissolved metal ions and metalloids, thereby detoxifying their environment. There are various bacteria cellular components such as enzymes, proteins, peptides, pigments, which are involved in the formation of nanoparticles. Bio-intensive manufacturing of NPs is environmentally friendly and inexpensive and requires low energy consumption. Some biosynthetic NPs are used as heterogeneous catalysts for environmental restoration, exhibiting higher catalytic efficiency due to their stability and increased biocompatibility. Bacteria used as nanofactories can provide a new approach to the removal of metal or metalloid ions and the production of materials with unique properties. Although a wide range of NPs have been biosynthetic and their synthetic mechanisms have been proposed, some of these mechanisms are not known in detail. This review focuses on the synthesis and catalytic applications of NPs obtained using bacteria. Known mechanisms of bioreduction and prospects for the development of NPs for catalytic applications are discussed

Optimization and kinetic study of pigments production on solid state fermentation using oil palm frond by monascus purpureus ftc 5357

Monascus sp. produce useful Monascus pigments that widely used in food industry. Extensive study available on Monascus sp. in solid-state fermentation (SSF) using shake flask, however, cultivation of Monascus sp. in stirred drum bioreactor is insufficiently reported. Thus, this study aims to optimize pigments production (i.e. yellow, orange and red) from Monascus purpureus FTC 5357 using oil palm frond (OPF) in 5 L stirred-drum bioreactor. Prior to the SSF process, hydrothermal treatment (121 °C, 15 min) was done. A three-level Box–Behnken design (BBD) was used for the optimization, with threeparameters such as initial moisture content (IMC), aeration rate (AR) and peptone concentration (PC). The dried fermented OPF were extracted and analysed for pigments production (i.e. yellow, orange and red), biomass and glucose concentration. Next, the kinetic profile of the optimize condition and kinetic parameters were also been evaluated. Based on the ANOVA analysis results, IMC, AR and PC contributed significantly to the pigments production. The optimal fermentation conditions resulted IMC at 70 % w/w, AR at 1.30 vvm and PC at 4.40 % w/w. Under these conditions, the pigments production were obtained at 22.03, 20.11 and 18.59 Au/g.d for yellow, orange and red, respectively. Validation experiment was done to confirm the adequacy of the models. The fermentation profile at optimized condition indicated that Monascus purpureus FTC 5357 reached maximum pigments and biomass at day 9. Results obtained from this study showed the importance of IMC, AR and PC for pigments production and biomass. Meanwhile, the production kinetic parameters such as maximum specific growth rate, the growth yield, pigment yield, cell productivity, pigments productivity for yellow, orange and red were 0.707 day-1, 0.15 mg/mg, 0.193 Au/mg cell and 12.514 mg/(g.day), 2.447 Au/(g.d.day), 2.234 Au/(g.d.day) and 2.065 Au/(g.d.day), respectively. The pigments produced through SSF process using OPF as a substrate by Monascus purpureus FTC 5357 has a great potential to be utilized as a source of pigment for food in future

Utilization of by-product of groundnut oil processing for production of prodigiosin by microbial fermentation and its novel potent anti-nematodes effect

[[abstract]]This study aimed to reuse groundnut oil processing by-product, groundnut cake (GNC) for the low-cost production of prodigiosin (PG) via microbial technology and to assess its novel potential application for the management of black pepper nematodes. Serratia marcescens TUN02 was found as the most active PG-producing strain. Various small-scale experiments conducted in flasks indicated that GNC at 1% may be used as the sole carbon/nitrogen source for cost-effective PG production by fermentation. Notably, no further commercial ingredients and salts are required to supplement into the culture medium of this fermentation. PG was further investigated for scale-up production in a 14-L bioreactor system and PG was produced at high yield (6886 mg/L) with large-scale volume (4 L) in a short cultivation time (10 h). PG was then purified and its nematicidal activity was evaluated and showed effective inhibition of juveniles and egg hatching of Meloidogyne incognita species, harmful on black pepper, with low IC50 values of 0.2 and 0.32 mg/mL, respectively. The simple medium containing 1% GNC is the first report of cost-effective biosynthesis of PG, as well as potential in vitro anti-egg hatching activity of PG. These results indicated the potential application of GNC for low-cost bioproduction of PG for promising and novel use in the management of black pepper nematodes.[[sponsorship]]MOST[[notice]]補正完