Aspergillus spp., a versatile cell factory for enzymes and metabolites: Interventions through genome editing

Aspergillus sp. is widely distributed in nature and plays significant roles in the degradation of lignocellulose biomass and extensively used in bioprocess and fermentation technology and many species are also a generally regarded safe. Many of the Aspergillus species are established cell factories due to their inherent capacity in secreting large number of hydrolytic enzymes. With the advent of next generation genomic technologies and metabolic engineering technologies, the production potential of Aspergillus cell factory has improved over the years. Various genome editing tools has been developed for Aspergillus like engineered nucleases, zinc finger nucleases, TALEN and CRISPR-Cas9 system. Currently, the CRISPR/Cas9-based technique is extensively used to enhance the effectiveness of gene manipulation in model system Aspergillus nidulans and other strains like Aspergillus oryzae, Aspergillus niger and Aspergillus fumigatus. This review describes the recent developments of genome editing technologies in Aspergillus the synthesis of heterologous proteins and secondary metabolites in the Aspergillus species

Bioconversion of waste cooking oil for the production of poly-3-hydroxybutyrate using Bacillus cereus MPTDC

Used cooking oil is generated as a byproduct during frying process. It cannot be reused for cooking process due to health issues such as cancer and other digestive disorders. Alternative strategy is utilization of this waste cooking oil for production of poly-3-hydroxybutyrate (PHB) a biopolymer which can be used as a substitute for petroleum derived plastics [ABG1] or other value added products. In the present investigation, we used waste cooking oil as carbon source for PHB production by Bacillus cereus MPTDC. The optimum conditions of PHB production by Bacillus cereus MPTDC were waste cooking oil concentration of 2% (v/v), incubation time of 96 h, ammonium sulphate concentration of 7.5% and yeast extract concentration of 0.2%. Under optimized conditions the strain produced 3.777 g/L of PHB. The results indicate the potential of used cooking oil as carbon source for PHB production by Bacillus cereus MPTDC

Bioconversion of waste cooking oil for the production of poly-3-hydroxybutyrate using Bacillus cereus MPTDC

557-562Used cooking oil is generated as a byproduct during frying process. It cannot be reused for cooking process due to health issues such as cancer and other digestive disorders. Alternative strategy is utilization of this waste cooking oil for production of poly-3-hydroxybutyrate (PHB) a biopolymer which can be used as a substitute for petroleum derived plastics or other value added products. In the present investigation, we used waste cooking oil as carbon source for PHB production by Bacillus cereus MPTDC. The optimum conditions of PHB production by Bacillus cereus MPTDC were waste cooking oil concentration of 2% (v/v), incubation time of 96 h, ammonium sulphate concentration of 7.5% and yeast extract concentration of 0.2%. Under optimized conditions the strain produced 3.777 g/L of PHB. The results indicate the potential of used cooking oil as carbon source for PHB production by Bacillus cereus MPTDC

Production of xylanase under submerged fermentation from Bacillus firmus HS11 isolated from Sikkim Himalayan region

Xylanase producing microorganisms isolated from high altitude soil show activity at broad window of temperature, and can have variety of industrial applications. Here, we explored production of xylanase under submerged fermentation from Bacillus firmus HS11 isolated from Sikkim Himalayan region. We isolated 472 bacterial strains high altitude soil samples (1120-4272 m) from Sikkim and screened for xylanase production. Among them five strains that showed higher xylanase activity were identified by 16s rRNA gene sequence analysis. comparatively, Bacillus firmus HS11 showed highest activity at 10, 37 and 50°C, and was chosen for optimization experiment. B. firmus HS11 showed xylanase activity of 3.35 U/mg of protein at 37°C and retained 32.43% activity at 10°C and had 79.82% higher activity at 50°C. Optimization of nutrient composition for submerged fermentation of B. firmus HS11 was carried out by combination of Plackett-Burman design and response surface methodology. The optimized media component for xylanase production by submerged fermentation by B. firmus HS11 is beechwood xylan 0.8% (w/v), MgSO4 0.04% (w/v), CaCl20.04% (w/v), peptone 0.1% (w/v), NaCl 0.3% (w/v) and yeast extracts 0.01% (w/v), resulting in enhancement of xylanase production by 7.4 folds. Xylanase having activity at broad range of temperature including lower temperature can have application in food industry

Optimization of Process Parameters for the Production of γ-Linolenic Acid by Cunninghamella elegans CFR C07 in Submerged Fermentation

U radu je ispitana proizvodnja γ-linolenske kiseline submerznom fermentacijom s pomoću gljivice Cunninghamella elegans CFR C07, te je proces optimiran odabirom najprikladnijeg izvora ugljika i optimalnog vremena inkubacije. Radi poboljšanja ekstrakcije lipida iz biomase nakon fermentacije ispitane su četiri različite metode: ekstrakcija pomoću otapala i pijeska tretiranog kiselinom, ekstrakcija pomoću otapala i staklenih kuglica, liofilizacija ili ekstrakcija u Soxhlet uređaju. Proizvodnja je γ-linolenske kiseline prvo optimirana u tikvici zapremnine 250 mL na tresilici, a zatim u fermentoru od 3 L. Postignut je prinos γ-linolenske kiseline od 882 mg/L na tresilici, te 733 mg/L u fermentoru. Rezultati istraživanja potvrđuju da je C. elegans CFR C07 odličan mikroorganizam za proizvodnju γ-linolenske kiseline u submerznim uvjetima.The production of γ-linolenic acid (GLA) by the fungus Cunninghamella elegans CFR C07 in submerged fermentation was studied. Culture parameters such as carbon source and incubation time were optimized. Four different extraction methods using solvents with acid washed sand, glass beads, lyophilization and Soxhlet extraction were evaluated for improved extraction of lipids from the fungal biomass after fermentation. The GLA production was initially optimized in 250-mL flask and the process was demonstrated in a 3-litre fermentor. The maximum GLA production was 882 mg/L in shake flask culture and 733 mg/L in the fermentor. The study shows that Cunninghamella elegans CFR C07 is a potent organism for the production of GLA under submerged conditions

Production of Pectinase from Bacillus sonorensis MPTD1

U radu je ispitanaproizvodnja pektinaze na podlozi s agarom s pomoću sedam sojeva bakterija izoliranih iz pokvarenog voća i povrća. Najučinkovitiji soj, MPTD1, identificiran je kao soj bakterije Bacillus sonorensis. Primjenom Plackett-Burman i Box-Behnken statističkih planova optimirani su različiti parametri, te je utvrđeno da udjeliekstrakta kvasca, K2HPO4,NaNO3i KCl te vrijeme inkubacije negativno utječu na proizvodnju pektinaze. Najveća postignuta aktivnost enzima bila je 2,43 (μM/mL)/min. U ovom je radu po prvi put opisana proizvodnja pektinaze s pomoću bakterije Bacillus sonorensis.Seven isolates from spoiled fruits and vegetables were screened for pectinase produc¬tion using pectin agar plates and the most efficient bacterial strain, MPTD1, was identified as Bacillus sonorensis. Optimisation of various process parameters was done using Plack¬ett-Burman and Box-Behnken designs and it was found that parameters like yeast extract, K2HPO4, incubation time, NaNO3 and KCl have a negative impact on pectinase production. Parameters like pH and MgSO4 and pectin mass fractions have a positive impact on pecti¬nase production. The maximum obtained enzyme activity was 2.43 (μM/mL)/min. This is the first report on pectinase production by Bacillus sonorensis

Applications of Microbial Enzymes in Food Industry

Uporaba enzima i mikroorganizama za pripremu hrane poznata je od davnina. S napretkom tehnologije razvijeni su novi enzimi specifičnih svojstava i širokog raspona primjene, te se neprestano traga za novim mogućnostima njihove uporabe. Bakterije, kvasci i gljivice te njihovi enzimi često se upotrebljavaju za pripremu hrane poboljšanog okusa i teksture, a ekonomski su isplativi. Mikrobni enzimi se koriste u većoj mjeri nego biljni i životinjski enzimi, i to zbog jednostavnije i jeftinije proizvodnje te njihove postojane kvalitete. U ovom se revijalnom prikazu raspravlja o najnovijim postignućima u tehnologiji proizvodnje enzima u prehrambenoj industriji. Naveden je opsežan popis enzima koji se koriste za obradu hrane, mikroorganizama iz kojih su proizvedeni, te je dan pregled njihove raznovrsne primjene.The use of enzymes or microorganisms in food preparations is an age-old process. With the advancement of technology, novel enzymes with wide range of applications and specificity have been developed and new application areas are still being explored. Microorganisms such as bacteria, yeast and fungi and their enzymes are widely used in several food preparations for improving the taste and texture and they offer huge economic benefits to industries. Microbial enzymes are the preferred source to plants or animals due to several advantages such as easy, cost-effective and consistent production. The present review discusses the recent advancement in enzyme technology for food industries. A comprehensive list of enzymes used in food processing, the microbial source of these enzymes and the wide range of their application are discussed

Recent advances in microbial biosynthesis of C3 – C5 diols: Genetics and process engineering approaches

Diols derived from renewable feedstocks have significant commercial interest in polymer, pharmaceutical, cosmetics, flavors and fragrances, food and feed industries. In C3-C5 diols biological processes of 1,3-propanediol, 1,2-propanediol and 2,3-butanediol have been commercialized as other isomers are non-natural metabolites and lack natural biosynthetic pathways. However, the developments in the field of systems and synthetic biology paved a new path to learn, build, construct, and test for efficient chassis strains. The current review addresses the recent advancements in metabolic engineering, construction of novel pathways, process developments aimed at enhancing in production of C3-C5 diols. The requisites on developing an efficient and sustainable commercial bioprocess for C3-C5 diols were also discusse

High level xylitol production by Pichia fermentans using non-detoxified xylose-rich sugarcane bagasse and olive pits hydrolysates

Hemicellulosic sugars, the overlooked fraction of lignocellulosic residues can serve as potential and cost-effective raw material that can be exploited for xylitol production. Xylitol is a top platform chemical with applications in food and pharmaceutical industries. Sugarcane bagasse (SCB) and olive pits (OP) are the major waste streams from sugar and olive oil industries, respectively. The current study evaluated the potential of Pichia fermentans for manufacturing of xylitol from SCB and OP hydrolysates through co-fermentation strategy. The highest xylitol accumulation was noticed with a glucose and xylose ratio of 1:10 followed by feeding with xylose alone. The fed-batch cultivation using pure xylose, SCB, and OP hydrolysates, resulted in xylitol accumulation of 102.5, 86.6 and 71.9 g/L with conversion yield of 0.78, 0.75 and 0.74 g/g, respectively. The non-pathogenic behaviour and ability to accumulate high xylitol levels from agro-industrial residues demonstrates the potential of P. fermentans as microbial cell factory

Process optimisation for production and recovery of succinic acid using xylose-rich hydrolysates by Actinobacillus succinogenes

Succinic acid (SA) is a top platform chemical obtainable from biomass. The current study evaluated the potential of Actinobacillus succinogenes for SA production using xylose-rich hemicellulosic fractions of two important lignocellulosic feedstocks, olive pits (OP) and sugarcane bagasse (SCB) and the results were compared with pure xylose. Initial experiments were conducted in shake flask followed by batch and fed-batch cultivation in bioreactor. Further separation of SA from the fermented broth was carried out by adapting direct crystallisation method. During fed-batch culture, maximum SA titers of 36.7, 33.6, and 28.7 g/L was achieved on pure xylose, OP and SCB hydrolysates, respectively, with same conversion yield of 0.27 g/g. The recovery yield of SA accumulated on pure xylose, OP and SCB hydrolysates was 79.1, 76.5, and 75.2%, respectively. The results obtained are of substantial value and pave the way for development of sustainable SA biomanufacturing in an integrated biorefinery