Enhanced production of mycelium biomass and exopolysaccharides of Pleurotus ostreatus by integrating response surface methodology and artificial neural network.

This study aimed to enhance the production of mycelium biomass and exopolysaccharides (EPS) of Pleurotus ostreatus in submerged fermentation. Response Surface Methodology (RSM)sought to optimize culture conditions, whereas Artificial Neural Network (ANN)aimed to predict the mycelium biomass and EPS. After optimization of RSM model conditions, the maximum biomass (36.45 g/L) and EPS (6.72 g/L) were obtained at the optimum temperature of 22.9 °C, pH 5.6, and agitation of 138.9 rpm. Further, the Genetic Algorithm (GA) was employed to optimize the cultivation conditions in order to maximize the mycelium biomass and EPS production. The ANN model with an optimized network structure gave the coefficient of determination (R2) value of 0.99 and the least mean squared error of 1.9 for the validation set. In the end, a graphical user interface was developed to predict mycelium biomass and EPS production.

An insight into the nutritional and medicinal value of edible mushrooms: A natural treasury for human health.

Edible mushrooms have been cherished worldwide because of their nutraceutical and medicinal properties. They are recognized as the new superfood for the future due to their low-calorie content, high-protein content, low lipid levels, low cholesterol levels, and abundance of essential vitamins. The fruiting body of edible mushrooms contains a plethora of primary and secondary metabolites. However, submerged cultivation is a more reliable and controlled way of production of mycelium biomass and many bioactive compounds. Several bioactive metabolites present in mushrooms possess a range of beneficial properties, including antioxidant, antimicrobial, anticancer, antidiabetic, anti-inflammatory, antiviral and anti-COVID-19 activities. Consumers have turned more intrigued in mushroom-containing products as the world needs to diversify its protein sources to meet the growing demand for protein. In this context, mushrooms are viewed as a promising source of bioactive chemicals that can be employed as an alternative to meat products. This review aims to summarise the most recent data regarding the beneficial health effects and the development of mushroom-based food products.

Microbes Producing L-Asparaginase free of Glutaminase and Urease isolated from Extreme Locations of Antarctic Soil and Moss.

L-Asparaginase (L-asparagine aminohydrolase, E.C. 3.5.1.1) has been proven to be competent in treating Acute Lymphoblastic Leukaemia (ALL), which is widely observed in paediatric and adult groups. Currently, clinical L-Asparaginase formulations are derived from bacterial sources such as Escherichia coli and Erwinia chrysanthemi. These formulations when administered to ALL patients lead to several immunological and hypersensitive reactions. Hence, additional purification steps are required to remove toxicity induced by the amalgamation of other enzymes like glutaminase and urease. Production of L-Asparaginase that is free of glutaminase and urease is a major area of research. In this paper, we report the screening and isolation of fungal species collected from the soil and mosses in the Schirmacher Hills, Dronning Maud Land, Antarctica, that produce L-Asparaginase free of glutaminase and urease. A total of 55 isolates were obtained from 33 environmental samples that were tested by conventional plate techniques using Phenol red and Bromothymol blue as indicators. Among the isolated fungi, 30 isolates showed L-Asparaginase free of glutaminase and urease. The L-Asparaginase producing strain Trichosporon asahii IBBLA1, which showed the highest zone index, was then optimized with a Taguchi design. Optimum enzyme activity of 20.57 U mL-1 was obtained at a temperature of 30 °C and pH of 7.0 after 60 hours. Our work suggests that isolation of fungi from extreme environments such as Antarctica may lead to an important advancement in therapeutic applications with fewer side effects.

Resistive room temperature LPG sensor based on a graphene/CdO nanocomposite.

The authors decribe an ultra-sensitive, room temperature, flexible transparent LPG sensor based on the use of a CdO/graphene nanocomposite. The graphene prevents the accumulation of CdO, enhances the surface area, and acts as a gas sensing material. FESEM images show a uniform decoration of CdO nanoparticles on graphene. The CdO/graphene composite was deposited as a film on interdigitated electrodes (IDEs) which then were used for chemiresistive sensing of liquid petroleum gas (LPG) by using a four probe technique. A Resistivity decreases significantly upon exposure to a LPG. The electrical resistance measurement at a constant bias voltage of 0.5 V. The sensor of type CdO/graphene (1 wt.%) exhibits a sensitivity of 600 ppm of LPG at 27 °C. It is a highly selective, stable and sensitive to low concentration of LPG even at room temperature. Graphical abstract The gas sensing properties of CdO/graphene nanocomposite with different weight percentages were studied using chemiresistive technique.

Flexible ultra-sensitive and resistive NO2 gas sensor based on nanostructured Zn(x)Fe(1-x)2O4.

Low concentration gas detection, rapid response time and low working temperature are anticipated for a varied range of toxic gas detection applications. Conversely, the existing gas sensors suffer mostly from a high working temperature along with a slow response at low concentrations of analytes. Here, we report an ultrasensitive flexible nanostructured Zn(x)Fe(1-x)2O4 (x = 0.1, 0.5 and 0.9) based chemiresistive sensor for nitrogen dioxide (NO2) detection. We evince that the prepared flexible sensor Zn(0.5)Fe(0.5)2O4 has detection potential as low as 5 ppm at a working temperature of 90 °C in a short phase. Further, the Zn(0.5)Fe(0.5)2O4 sensor exhibits excellent selectivity, stability and repeatability. The optimized sensor sensing characteristics can be helpful in tremendous development of foldable mobile devices for environmental monitoring, protection and control.

Different methodologies for sustainability of optimization techniques used in submerged and solid state fermentation.

Optimization techniques are considered as a part of nature's way of adjusting to the changes happening around it. There are different factors that establish the optimum working condition or the production of any value-added product. A model is accepted for a particular process after its sustainability has been verified on a statistical and analytical level. Optimization techniques can be divided into categories as statistical, nature inspired and artificial neural network each with its own benefits and usage in particular cases. A brief introduction about subcategories of different techniques that are available and their computational effectivity will be discussed. The main focus of the study revolves around the applicability of these techniques to any particular operation such as submerged fermentation (SmF) and solid state fermentation (SSF), their ability to produce secondary metabolites and the usefulness in the laboratory and industrial level. Primary studies to determine the enzyme activity of different microorganisms such as bacteria, fungi and yeast will also be discussed. l-Asparaginase, the most commonly used drugs in the treatment of acute lymphoblastic leukemia (ALL) shall be considered as an example, a short discussion on models used in the production by the processes of SmF and SSF will be discussed to understand the optimization techniques that are being dealt. It is expected that this discussion would help in determining the proper technique that can be used in running any optimization process for different purposes, and would help in making these processes less time-consuming with better output.

Room temperature LPG resistive sensor based on the use of a few-layer graphene/SnO2 nanocomposite.

A nanocomposite consisting of a few layers of graphene (FLG) and tin dioxide (SnO2) was prepared by ultrasound-assisted synthesis. The uniform SnO2 nanoparticles (NPs) on the FLG were characterized by X-ray diffraction in terms of lattice and phase structure. The functional groups present in the composite were analyzed by FTIR. Electron microscopy (HR-TEM and FE-SEM) was used to study the morphology. The effect of the fraction of FLG present in the nanocomposite was investigated. Sensitivity, selectivity and reproducibility towards resistive sensing of liquid propane gas (LPG) was characterized by the I-V method. The sensor with 1% of FLG on SnO2 operated at a typical voltage of 1 V performs best in giving a rapid and sensitive response even at 27 °C. This proves that the operating temperature of such sensors can be drastically decreased which is in contrast to conventional metal oxide LPG sensors. Graphical abstract Schematic of a room temperature gas sensor for liquefied petroleum gas (LPG). It is based on the use of a few-layered graphene (1 wt%)/SnO2 nanocomposite that was deposited on an interdigitated electrode (IDEs). A sensing mechanism for LPG detection has been established.

Isolation and screening of L-asparaginase free of glutaminase and urease from fungal sp.

L-Asparaginase is a chemotherapeutic drug used in the treatment of acute lymphoblastic leukaemia (ALL), a malignant disorder in children. L-Asparaginase helps in removing acrylamide found in fried and baked foods that is carcinogenic in nature. L-Asparaginase is present in plants, animals and microbes. Various microorganisms such as bacteria, yeast and fungi are generally used for the production of L-asparaginase as it is difficult to obtain the same from plants and animals. L-Asparaginase from bacteria causes anaphylaxis and other abnormal sensitive reactions due to low specificity to asparagine. Toxicity and repression caused by bacterial L-asparaginase shifted focus to eukaryotic microorganisms such as fungi to improve the efficacy of L-asparaginase. Clinically available L-asparaginase has glutaminase and urease that may lead to side effects during treatment of ALL. Current work tested 45 fungal strains isolated from soil and agricultural residues. Isolated fungi were tested using conventional plate assay method with two indicator dyes, phenol red and bromothymol blue (BTB), and results were compared. L-Asparaginase activity was measured by cultivating in modified Czapek-Dox medium. Four strains have shown positive result for L-asparaginase production with no urease or glutaminase activity, among these C7 has high enzyme index of 1.57 and L-asparaginase activity of 33.59 U/mL. L-Asparaginase production by C7 was higher with glucose as carbon source and asparagine as nitrogen source. This is the first report focussing on fungi that can synthesize L-asparaginase of the desired specificity. Since the clinical toxicity of L-asparaginase is attributed to glutaminase and urease activity, available evidence indicates variants negative for glutaminase and urease would provide higher therapeutic index than variants positive for glutaminase and urease.