Robustness of FTIR-Based Ultrarapid COVID-19 Diagnosis Using PLS-DA.

The World Health Organization (WHO) declared the Omicron variant (B.1.1.529) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen responsible for the Coronavirus disease 2019 (COVID-19) pandemic, as a variant of concern on 26 November 2021. By this time, 42% of the world's population had received at least one dose of the vaccine against COVID-19. As on 1 October 2022, only 68% of the world population got the first dose of the vaccine. Although the vaccination is incredibly protective against severe complications of the disease and death, the highly contagious Omicron variant, compared to the Delta variant (B.1.617.2), has led the whole world into more chaotic situations. Furthermore, the virus has a high mutation rate, and hence, the possibility of a new variant of concern in the future cannot be ruled out. To face such a challenging situation, paramount importance should be given to rapid diagnosis and isolation of the infected patient. Current diagnosis methods, including reverse transcription-polymerase chain reaction and rapid antigen tests, face significant burdens during a COVID-19 wave. However, studies reported ultrarapid, reagent-free, cost-efficient, and non-destructive diagnosis methods based on chemometrics for COVID-19 and COVID-19 severity diagnosis. These studies used a smaller sample cohort to construct the diagnosis model and failed to discuss the robustness of the model. The current study systematically evaluated the robustness of the diagnosis models trained using smaller (real and augmented spectra) and larger (augmented spectra) datasets. The Monte Carlo cross-validation and permutation test results suggest that diagnosis using models trained by larger datasets was accurate and statistically significant (Q 2 > 99% and AUROC = 100%).

Production of polyhydroxyalkanoates from propylene oxide saponification wastewater residual sludge using volatile fatty acids and bacterial community succession.

The active sludge treating propylene oxide saponification wastewater has heavy salt concentration and is hard to treat. The integration of the residual sludge treatment with polyhydroxyalkanoates (PHA) production may provide an economic and environment friendly solution. PHA production was therefore studied in two sequencing biological reactors with effective volume of 30 L using the active sludge. The two reactors, named as SBR-I and SBR-II, were fed with acetic acid, and a mixture of acetic acid and propionic acid respectively. PHA was obtained with a yield of 9.257 g/L in SBR-II. Also, the proportion of 3-hydroxyvalarate was enhanced from 5% to 30% in comparison to SBR-I (5.471 g/L). Illumina MiSeq and Pacific Biosciences sequencing platforms were used to evaluate the community structure, which revealed that the bacterial genera showed a high degree of diversity in the PHA accumulating microbial community. Azoarcus was the most dominant PHA accumulating microorganism after acclimation.

Sustainable and eco-friendly strategies for shrimp shell valorization.

Among the seafood used globally, shellfish consumption is in great demand. The utilization of these shellfish such as prawn/shrimp has opened a new market for the utilization of the shellfish wastes. Considering the trends on the production of wealth from wastes, shrimp shell wastes seem an important resource for the generation of high value products when processed on the principles of a biorefinery. In recent years, various chemical strategies have been tried to valorize the shrimp shell wastes, which required harsh chemicals such as HCl and NaOH for demineralization (DM) and deproteination (DP) of the shrimp wastes. Disposal of chemicals by the chitin and chitosan industries into the aquatic bodies pose harm to the aquatic flora and fauna. Thus, there has been intensive efforts to develop safe and sustainable technologies for the management of shrimp shell wastes. This review provides an insight about environmentally-friendly methods along with biological methods to valorize the shrimp waste compared to the strategies employing concentrated chemicals. The main objective of this review article is to explain the utilization shrimp shell wastes in a productive manner such that it would be offer environment and economic sustainability. The application of valorized by-products developed from the shrimp shell wastes and physical methods to improve the pretreatment process of shellfish wastes for valorization are also highlighted in this paper.

Tandem integration of aerobic fungal cellulase production, lignocellulose substrate saccharification and anaerobic ethanol fermentation by a modified gas lift bioreactor.

Cellulase production, lignocellulose saccharification and bioethanol fermentation were integrated to efficiently produce bioethanol. A modified gas lift bioreactor was developed for bioethanol production by the integrated process. Cellulase production was achieved using Aspergillus niger mycelia immobilized within the reactor in wire meshes, and Saccharomyces cerevisiae cells were immobilized in resin beads. During four repeated batches fermentation, cellulase activities were more than 6.28 U/mL and bioethanol production was over 45.9 g/L for 48 h. The factual bioethanol conversion efficiency was 86.8%. By the modification of the modified gas lift bioreactor, immobilization of Aspergillus niger mycelia and Saccharomyces cerevisiae cells, aerobic cellulase production, substrate saccharification and anaerobic bioethanol fermentation were successfully integrated in tandem. The integrated processes is of great significance in bioethanol production.

Lipase of Pseudomonas guariconesis as an additive in laundry detergents and transesterification biocatalysts.

A newly isolated culture, Pseudomonas guariconesis, is reported for the first time for lipase production. Various process parameters affecting enzyme production were optimized through statistical design experiments. The Plackett-Burman experimental design was used for screening 10 parameters for lipase production, which was further optimized using the central composite design of response surface methodology. Maximum lipase activity of 220 U/ml was obtained after 24 h of incubation in shake-flask cultures with an inoculum concentration of 0.6% v/v, incubation temperature of 30°C, and medium pH 9.0. Castor oil (0.5% v/v) was used as the inducer for lipase production. The enzyme was found to be compatible with five different commercial detergents, indicating its potential to be used in detergent formulations. It also acted as a biocatalyst in a transesterification process. The alkaline enzyme was found to be stable in the presence of bleaching agents, metal ions, and organic solvents as well.

Detoxification of acidic biorefinery waste liquor for production of high value amino acid.

The current study evaluates the detoxification of acid pretreatment liquor (APL) using adsorbent (ADS 400 & ADS 800) or ion-exchange (A-27MP & A-72MP) resins and its potential for amino acid production. The APL is generated as a by-product from the pretreatment of lignocellulosic biomass and is rich monomeric sugars as well as sugar degradation products (fermentation inhibitors) such as furfural and hydroxymethyl furfural (HMF). Of the four resins compared, ADS 800 removed approximately 85% and 60% of furfural and HMF, respectively. ADS 800 could be reused for up to six cycles after regeneration without losing its adsorption properties. The study was further extended by assessing the fermentability of detoxified APL for l-lysine production using wild and mutant strains of Corynebacterium glutamicum. The detoxified APL was superior to APL for l-lysine production.

An evaluation of dilute acid and ammonia fiber explosion pretreatment for cellulosic ethanol production.

The challenge associated with cellulosic ethanol production is maximizing sugar yield at low cost. Current research is being focused to develop a pretreatment method to overcome biomass recalcitrance in an efficient way. This review is focused on two major pretreatments: dilute acid (DA) and ammonia fiber explosion (AFEX) pretreatment of corn stover and how these pretreatment cause morphological and chemical changes to corn stover in order to overcome the biomass recalcitrance. This review highlights the key differences of these two pretreatments based on compositional analysis, cellulose and its crystallinity, morphological changes, structural changes to lignin, enzymatic reactivity and enzyme adsorption onto pretreated solids and finally cellulosic ethanol production from the hydrolysate of DA and AFEX treated corn stover. Each stage of the process, AFEX pretreated corn stover was superior to DA treated corn stover.

Crude oil biodegradation aided by biosurfactants from Pseudozyma sp. NII 08165 or its culture broth.

The aim of this work was to evaluate the biosurfactants produced by the yeast Pseudozyma sp. NII 08165 for enhancing the degradation of crude oil by a model hydrocarbon degrading strain, Pseudomonas putida MTCC 1194. Pseudozyma biosurfactants were supplemented at various concentrations to the P. putida culture medium containing crude oil as sole carbon source. Supplementation of the biosurfactants enhanced the degradation of crude oil by P. putida; the maximum degradation of hydrocarbons was observed with a 2.5 mg L(-1) supplementation of biosurfactants. Growth inhibition constant of the Pseudozyma biosurfactants was 11.07 mg L(-1). It was interesting to note that Pseudozyma sp. NII 08165 alone could also degrade diesel and kerosene. Culture broth of Pseudozyma containing biosurfactants resulted up to ∼46% improvement in degradation of C10-C24 alkanes by P. putida. The enhancement in degradation efficiency of the bacterium with the culture broth supplementation was even more pronounced than that with relatively purer biosurfactants.

Hydrolysis of biomass using a reusable solid carbon acid catalyst and fermentation of the catalytic hydrolysate to ethanol.

Solid acid catalysts can hydrolyze cellulose with lower reaction times and are easy to recover and reuse. A glycerol based carbon acid catalyst developed at CSIR-IICT performed well in acid catalysis reactions and hence this study was undertaken to evaluate the catalyst for hydrolysis of biomass (alkali pretreated or native rice straw). The catalyst could release 262 mg/g total reducing sugars (TRS) in 4h at 140 °C from alkali pretreated rice straw, and more importantly it released 147 mg/g TRS from native biomass. Reusability of the catalyst was also demonstrated. Catalytic hydrolysate was used as sugar source for fermentation to produce ethanol. Results indicate the solid acid catalyst as an interesting option for biomass hydrolysis.

Prediction of sugar yields during hydrolysis of lignocellulosic biomass using artificial neural network modeling.

The present investigation was carried out to study application of ANN as a tool for predicting sugar yields of pretreated biomass during hydrolysis process at various time intervals. Since it is known that biomass loading and particle size influences the rheology and mass transfer during hydrolysis process, these two parameters were chosen for investigating the efficiency of hydrolysis. Alkali pretreated rice straw was used as the model feedstock in this study and biomass loadings were varied from 10% to 18%. Substrate particle sizes used were <0.5mm, 0.5-1mm, >1mm and mixed size. Effectiveness of hydrolysis was strongly influenced by biomass loadings, whereas particle size did not have any significant impact on sugar yield. Higher biomass loadings resulted in higher sugar concentration in the hydrolysates. Optimum hydrolysis conditions predicted were 10 FPU/g cellulase, 5 IU/g BGL, 7500 U/g xylanase, 18% biomass loading and mixed particle size with reaction time between 12-28 h.

Highly glucose tolerant ß-glucosidase from Aspergillus unguis: NII 08123 for enhanced hydrolysis of biomass.

Aspergillus unguis NII-08123, a filamentous fungus isolated from soil, was found to produce ß-glucosidase (BGL) activity with high glucose tolerance. Cultivation of the fungus in different carbon sources resulted in the secretion of different isoforms of the enzyme. A low molecular weight isoform, which retained ~60 % activity in the presence of 1.5 M glucose, was purified to homogeneity and the purified enzyme exhibited a temperature and pH optima of 60 °C and 6, respectively. The K(m) and V(max) of the enzyme were 4.85 mM and 2.95 U/mg, respectively, for 4-nitrophenyl ß-D-glucopyranoside. The glucose inhibition constant of the enzyme was 0.8 M, indicating high glucose tolerance, and this is the second-highest glucose tolerance ever reported from the Aspergillus nidulans group. The glucose-tolerant BGL from A. unguis, when supplemented to cellulase preparation from Penicillium, could improve biomass hydrolysis efficiency by 20 % in 12 h compared to the enzyme without additional beta glucosidase supplementation. The beta glucosidase from A. unguis is proposed as a highly potent "blend-in" for biomass saccharifying enzyme preparations.

Biobutanol production from rice straw by a non acetone producing Clostridium sporogenes BE01.

Biobutanol from lignocellulosic biomass has gained much attention due to several advantages over bioethanol. Though microbial production of butanol through ABE fermentation is an established technology, the use of lignocellulosic biomass as feedstock presents several challenges. In the present study, biobutanol production from enzymatic hydrolysate of acid pretreated rice straw was evaluated using Clostridium sporogenes BE01. This strain gave a butanol yield of 3.43 g/l and a total solvent yield of 5.32 g/l in rice straw hydrolysate supplemented with calcium carbonate and yeast extract. Hydrolysate was analyzed for the level of inhibitors such as acetic acid, formic acid and furfurals which affect the growth of the organism and in turn ABE fermentation. Methods for preconditioning the hydrolysate to remove toxic end products were done so as to improve the fermentation efficiency. Conditions of ABE fermentation were fine tuned resulting in an enhanced biobutanol reaching 5.52 g/l.

Energy requirement for alkali assisted microwave and high pressure reactor pretreatments of cotton plant residue and its hydrolysis for fermentable sugar production for biofuel application.

In the present work, alkali assisted microwave pretreatment (AAMP) of cotton plant residue (CPR) with high pressure reactor pretreatment was compared. Further, modeling of AAMP was attempted. AAMP, followed by enzymatic saccharification was evaluated and the critical parameters were identified to be exposure time, particle size and enzyme loading. The levels of these parameters were optimized using response surface methodology (RSM) to enhance sugar yield. AAMP of CPR (1mm average size) for 6 min at 300 W yielded solid fractions that on hydrolysis resulted in maximum reducing sugar yield of 0.495 g/g. The energy required for AAMP at 300 W for 6 min was 108 kJ whereas high pressure pretreatment (180°C, 100 rpm for 45 min) requires 5 times more energy i.e., 540 kJ. Physiochemical characterization of native and pretreated feedstock revealed differences between high pressure pretreatment and AAMP.

Surfactant-assisted acid pretreatment of sugarcane tops for bioethanol production.

Sugarcane tops is one of the largest biomass resources in India and in tropical countries such as Brazil in terms of surplus availability. Conversion of this feedstock to ethanol requires pretreatment to make it more accessible for the enzymes used in saccharification. Though several pretreatment regimens have been developed for addressing biomass recalcitrance, very few seem to be promising as an industrial process. A novel hybrid method involving use of mild acid and surfactant was developed which could effectively remove lignin and improve the sugar yield from sugar cane tops. Operational parameters that affect the pretreatment efficiency (measured as yield of sugars) were studied and optimized. Changes in structural properties of the biomass were studied in relation to the pretreatment process using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier Transform Infrared (FTIR) analysis, and the changes in chemical composition was also monitored. The biomass pretreated with the optimized novel method could yield 0.798 g of reducing sugars per gram of pretreated biomass upon enzymatic hydrolysis.

Formic acid as a potential pretreatment agent for the conversion of sugarcane bagasse to bioethanol.

In recent years, growing attention has been focused on the use of lignocellulosic biomass as a feedstock for the production of ethanol, a possible renewable alternative to fossil fuels. Several pretreatment processes have been developed for decreasing the biomass recalcitrance, but only a few of them seem to be promising. In this study, effect of various organic solvents and organic acids on the pretreatment of sugarcane bagasse was studied. Among the different organic acids and organic solvents tested, formic acid was found to be effective. Optimization of process parameters for formic acid pretreatment was carried out. The structural changes before and after pretreatment was investigated by scanning electron microscopy, X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The X-ray diffraction profile showed that the degree of crystallinity was more for pretreated biomass than that of untreated. The FTIR spectra shown at the stretching of hydrogen bonds of pretreated sugarcane bagasse arose at higher number. It also revealed that the cellulose content in the solid residue increased because the hemicelluloses fraction in raw materials was released by acid hydrolytic reaction.

Utilization of rice straw for laccase production by Streptomyces psammoticus in solid-state fermentation.

Laccase production from a novel actinobacterial strain, Streptomyces psammoticus, MTCC 7334 was optimized in solid-state fermentation. The process parameters were initially optimized by the conventional "one factor at a time" approach, and the optimal levels of the factors that had considerable influence on enzyme production were identified by response surface methodology. Rice straw was identified as a suitable substrate for laccase production (17.3 U/g), followed by coffee pulp (15.8 U/g). Other optimized conditions were particle size, 500-1,000 mum (21.2 U/g); initial moisture content, 65% (26.8 U/g); pH of moistening solution, 8.0 (26.9 U/g); incubation temperature, 32 degrees C (27.6 U/g) and inoculum size, 1.5 x 10(7) CFU (33.8 U/g). Yeast extract served as the best nitrogen source (34.8 U/g). No enhancement in enzyme yield was observed with carbon supplementation. The level of yeast extract, inoculum size and copper sulphate were optimized statistically. Statistical optimization performed using a central composite design resulted in threefold increase in laccase activity (55.4 U/g) as compared to the unoptimized medium (17.3 U/g). The upgrading of fermented rice straw for fodder enhancement is also discussed briefly.