A concise review on waste biomass valorization through thermochemical conversion.

Due to an increase in industrialization and urbanization, massive amounts of solid waste biomass are speedily accumulating in our environment, which poses several adverse effects on habitat and human health thus becoming a matter of discussion in the environmental community. With reference to the circular economy, continuous efforts have been put forward for setting up an organised management approach in combination with an efficient treatment technique for increasing the profitable utilization of solid waste. This review aims to provide a systematic discussion on the recent thermochemical technologies employed for converting waste biomass generated from different sources into valuable products like biochar, bio-oil, heat, energy and syngas. The article further focuses on a few important aspects of thermochemical conversion of waste biomass to useful products like technical factors affecting thermochemical processes, applications of by-products of thermochemical conversion, and biological pretreatment of waste biomass. The review assists interesting recent and scientific trends for boosting up the systematic management and valorization of solid waste through low-cost, efficient, environment-friendly and sustainable technologies.

Exogenous GABA supplementation to facilitate Cr (III) tolerance and lipid biosynthesis in Chlorella sorokiniana.

Microalgae possess the prospective to be efficiently involved in bioremediation and biodiesel generation. However, conditions of stress often restrict their growth and diminish different metabolic processes. The current study evaluates the potential of GABA to improve the growth of the microalga Chlorella sorokiniana under Cr (III) stress through the exogenous administration of GABA. The research also investigates the concurrent impact of GABA and Cr (III) stress on various metabolic and biochemical pathways of the microalgae. In addition to the control, cultures treated with Cr (III), GABA, and both Cr (III) and GABA treated were assessed for accurately analysing the influence of GABA. The outcomes illustrated that GABA significantly promoted growth of the microalgae, resulting in higher biomass productivity (19.14 mg/L/day), lipid productivity (3.445 mg/L/day) and lipid content (18%) when compared with the cultures under Cr (III) treatment only. GABA also enhanced Chl a content (5.992 µg/ml) and percentage of protein (23.75%). FAMEs analysis by GC-MS and total lipid profile revealed that GABA treatment can boost the production of SFA and lower the level of PUFA, a distribution ideal for improving biodiesel quality. ICP-MS analysis revealed that GABA supplementation could extend Cr (III) mitigation level up to 97.7%, suggesting a potential strategy for bioremediation. This novel study demonstrates the merits of incorporating GABA in C. sorokiniana cultures under Cr (III) stress, in terms of its potential in bioremediation and biodiesel production without disrupting the pathways of photosynthesis and protein production.

Algae: A promising and sustainable protein-rich food ingredient for bakery and dairy products.

The consumer demand for protein rich foods urges the exploration for novel products of natural origin. Algae can be considered as a gold mine of different bioactive compounds, among which protein is distributed in significant amounts i.e., around 30% and can even reach to 55-60% in some cyanobacteria. Bakery and dairy products are extensively consumed worldwide due to product diversification and innovation. However, incorporation of algae biomass can lead to the development of green colour and fishy flavour that usually is not accepted in such products. Therefore, isolation and application of algae-derived proteins opens a new door for food industry. The present review provides a comprehensive understanding of incorporation of algae as a protein-rich ingredient in bakery and dairy products. The paper provides a deep insight for all the possible recent trends related to production and extraction of algae proteins accompanied by their incorporation in bakery and dairy foods.

A concise review on wastewater treatment through microbial fuel cell: sustainable and holistic approach.

Research for alternative sources for producing renewable energy is rising exponentially, and consequently, microbial fuel cells (MFCs) can be seen as a promising approach for sustainable energy production and wastewater purification. In recent years, MFC is widely utilized for wastewater treatment in which the removal efficiency of heavy metal ranges from 75-95%. They are considered as green and sustainable technology that contributes to environmental safety by reducing the demand for fossil fuels, diminishes carbon emissions, and reverses the trend of global warming. Moreover, significant reduction potential can be seen for other parameters such as total carbon oxygen demand (TCOD), soluble carbon oxygen demand (SCOD), total suspended solids (TSS), and total nitrogen (TN). Furthermore, certain problems like economic aspects, model and design of MFCs, type of electrode material, electrode cost, and concept of electro-microbiology limit the commercialization of MFC technology. As a result, MFC has never been accepted as an appreciable competitor in the area of treating wastewater or renewable energy. Therefore, more efforts are still required to develop a useful model for generating safe, clean, and CO2 emission-free renewable energy along with wastewater treatment. The purpose of this review is to provide a deep understanding of the working mechanism and design of MFC technology responsible for the removal of different pollutants from wastewater and generate power density. Existing studies related to the implementation of MFC technology in the wastewater treatment process along with the factors affecting its functioning and power outcomes have also been highlighted.

Enhancing the bio-prospective of microalgae by different light systems and photoperiods.

Microalgae are a source of highly valuable bioactive metabolites and a high-potential feedstock for environmentally friendly and sustainable biofuel production. Recent research has shown that microalgae benefit the environment using less water than conventional crops while increasing oxygen production and lowering CO2 emissions. Microalgae are an excellent source of value-added compounds, such as proteins, pigments, lipids, and polysaccharides, as well as a high-potential feedstock for environmentally friendly and sustainable biofuel production. Various factors, such as nutrient concentration, temperature, light, pH, and cultivation method, effect the biomass cultivation and accumulation of high-value-added compounds in microalgae. Among the aforementioned factors, light is a key and essential factor for microalgae growth. Since photoautotrophic microalgae rely on light to absorb energy and transform it into chemical energy, light has a significant impact on algal growth. During micro-algal culture, spectral quality may be tailored to improve biomass composition for use in downstream bio-refineries and boost production. The light regime, which includes changes in intensity and photoperiod, has an impact on the growth and metabolic composition of microalgae. In this review, we investigate the effects of red, blue, and UV light wavelengths, different photoperiod, and different lighting systems on micro-algal growth and their valuable compounds. It also focuses on different micro-algal growth, photosynthesis systems, cultivation methods, and current market shares.

Impact of irradiation on physico-chemical and nutritional properties of fruits and vegetables: A mini review.

Background: Fruits and vegetables are healthy because they contain good nutrients and secondary metabolites that keep the body healthy and disease-free. Post-harvest losses of fresh fruits and vegetables limit access and availability as a result of foodborne infections and poor storage technologies. The selection of fruits and vegetables depend on the starting microbial load, the size of fruits and vegetables, and the type of infrastructure. Scope and approach: Despite the positive impacts of conventional thermal (roasting, boiling, blanching) and some non-thermal processing techniques such as High Pressure Processing (HPP), Pulse Electric Field (PEF), Cold Plasma Technology (CPT) on shelf-life extension, their use is commonly associated with a number of negative consequences on product quality such as cold plasma treatment increases the acidity and rate of lipid oxidation and further decrease the colour intensity and firmness of products. Similarly, in high pressure processing and pulse electric field there is no spore inactivation and they further limit their application to semi-moist and liquid foods. On that account, food irradiation, a non-thermal technique, is currently being used for post-harvest preservation, which could be very useful in retaining the keeping quality of various fresh and dehydrated products without negatively affecting their versatility and physico-chemical, nutritional and sensory properties. Conclusion: Existing studies have communicated the effective influence of irradiation technology on nutritional, sensory, and physico-chemical properties of multiple fruits and vegetables accompanying consequential deduction in microbial load throughout the storage period. Food irradiation can be recognized as a prevalent, safe and promising technology however, still is not fully exploited on a magnified scale. The consumer acceptance of processed products has always been a significant challenge for innovative food processing technologies such as food irradiation. Therefore, owing to current review, additional scientific evidences and efforts are still demanded for increasing its technological request.

Cold plasma technology: advanced and sustainable approach for wastewater treatment.

Cold plasma has been a potent energy-efficient and eco-friendly advanced oxidation technology which has gained attention in recent decades as a non-thermal approach in diverse forms of applications. This review highlights a comprehensive account of the implementation of this technology in the field of wastewater treatment to resolve certain issues regarding the degradation of numerous aqueous pollutants and water-borne pathogenic microorganisms including viruses up to a significant level. The paper addresses plasma chemistry sources and mechanisms on wastewater treatment and impact on various physical, chemical, and biological characteristics of treated water. Furthermore, studies have revealed that this emerging technology is effective in inactivating SARS-CoV-2 or coronavirus, which serves as a transmission channel for this lethal virus in wastewater. Despite these benefits, the development of cold plasma as a wastewater treatment technique is still hampered by a lack of information like capital investment, proficient application, liveability, and operating cost, thus necessitating additional research for its booming commercialization, as this can be an emerging approach to solving water crises and meeting the demand for fresh or potable water resources.

Production of solasodine by Solanum laciniatum using plant tissue culture technique.

Leaf and hypocotyl explants of 15 days old aseptically grown seedlings of Solanum laciniatum were cultured on MS medium supplemented with NAA (2 mg/l) and kinetin (0.5 mg/l) for callus initiation. For maintenance and proliferation of callus MS medium supplemented with 2,4-D (1 mg/l) and kinetin (0.5 mg/l) was used. The growth of the calli derived from hypocotyls increased with time of incubation and remained almost constant after 45 days. The solasodine content in callus culture was maximum after 30 days of incubation. Addition of L-arginine in the medium (50-150 mg/l) increased growth as well as chlorophyll content in the callus culture. The solasodine content also increased up to 1.2 to 1.4 times in these cultures. High frequency shoot regeneration was obtained in MS medium having BA (4 mg/l) and IBA (0.25 mg/l). For shoot multiplication, MS medium having BA (4 mg/l) was used. Shoots rooted on the same medium. Organogenesis promoted solasodine accumulation in the cultures. Regenerated shoots yielded higher solasodine content than undifferentiated as well as organogenic callus. Solasodine contents in the regenerated shoots was found to be 10 times higher than the callus culture and approached towards the field grown plants. Thin layer chromatography revealed the presence of three compounds. The most predominant spot (Rf 0.789) corresponded to the reference solasodine.