Futuristic advancements in phytoremediation of endocrine disruptor Bisphenol A: A step towards sustainable pollutant degradation for rehabilitated environment.

Bisphenol A (BPA) accumulates in the environment at lethal concentrations because of its high production rate and utilization. BPA, originating from industrial effluent, plastic production, and consumer products, poses serious risks to both the environment and human health. The widespread aggregation of BPA leads to endocrine disruption, reactive oxygen species-mediated DNA damage, epigenetic modifications and carcinogenicity, which can disturb the normal homeostasis of the body. The living being in a population is subjected to BPA exposure via air, water and food. Globally, urinary analysis reports have shown higher BPA concentrations in all age groups, with children being particularly susceptible due to its occurrence in items such as milk bottles. The conventional methods are costly with a low removal rate. Since there is no proper eco-friendly and cost-effective degradation of BPA reported so far. The phytoremediation, green-biotechnology based method which is a cost-effective and renewable resource can be used to sequestrate BPA. Phytoremediation is observed in numerous plant species with different mechanisms to remove harmful contaminants. Plants normally undergo several improvements in genetic and molecular levels to withstand stress and lower levels of toxicants. But such natural adaptation requires more time and also higher concentration of contaminants may disrupt the normal growth, survival and yield of the plants. Therefore, natural or synthetic amendments and genetic modifications can improve the xenobiotics removal rate by the plants. Also, constructed wetlands technique utilizes the plant's phytoremediation mechanisms to remove industrial effluents and medical residues. In this review, we have discussed the limitations and futuristic advancement strategies for degrading BPA using phytoremediation-associated mechanisms.

Comprehensive review on recent production trends and applications of biochar for greener environment.

The suitability of biochar as a supplement for environmental restoration varies significantly based on the type of feedstocks used and the parameters of the pyrolysis process. This study comprehensively examines several aspects of biochar's potential benefits, its capacity to enhance crop yields, improve nutrient availability, support the co-composting, water restoration and enhance overall usage efficiency. The supporting mechanistic evidence for these claims is also evaluated. Additionally, the analysis identifies various gaps in research and proposes potential directions for further exploration to enhance the understanding of biochar application. As a mutually advantageous approach, the integration of biochar into agricultural contexts not only contributes to environmental restoration but also advances ecological sustainability. The in-depth review underscores the diverse suitability of biochar as a supplement for environmental restoration, contingent upon the specific feedstock sources and pyrolysis conditions used. However, concerns have been raised regarding potential impacts on human health within agricultural sectors.

Xylopentose production from crop residue employing xylanase enzyme.

To produce xylo-oligosaccharides (XOS) from the agriculture waste, which included, green coconut and vegetable cocktail. The two pretreatment - hydrogen peroxide-acetic acid (HP-AC) and sodium hypochlorite-sodium hydroxide (SH-SH) - were used for this study. The optimal conditions for the pretreatment were 80 °C, 4.0 % NaClO, and 2 h, followed by 0.08 % NaOH, 55 °C, and 1 h. Further enzymatic hydrolysis of green coconut (GC) and vegetable cocktail (VC) were performed and found in case of GC, the best outcomes were observed. Different types of XOS were obtained from the treated biomass whereas a single type of XOS xylo-pentose was obtained in high quantity (96.44 % and 93.09 % from CG and VC respectively) with the production of other XOS < 2 %. This study presents a reasonably secure and economical method for turning secondary crop residue into XOS and fermentable sugars.

A critical review on utilization of sewage sludge as environmental functional materials.

Sewage sludge (SS) is increasingly used as an environment functional material to reduce or control pollution and improve plant growth because of the large amounts of carbon and essential plant nutrients in it. To achieve the best application results, it is essential to comprehensively review recent progress in SS utilization. This review aims to fill the gaps in knowledge by describing the properties of SS, and its usage as adsorbents, catalysts and fertilizers, and certain application mechanisms. Although SS generates several benefits for the environment and humans, many challenges still exist to limit the application, including the risks posed by potentially toxic substances (e.g., heavy metals) in SS. Therefore, future research directions are discussed and how to make SS applications more feasible in terms of technology and economy.

Syntrophic bacteria- and Methanosarcina-rich acclimatized microbiota with better carbohydrate metabolism enhances biomethanation of fractionated lignocellulosic biocomponents.

An inadequate lignocellulolytic capacity of a conventional anaerobic digester sludge (ADS) microbiota is the bottleneck for the maximal utilization of lignocellulose in anaerobic digestion. A well-constructed microbial consortium acclimatized to lignocellulose outperformed the ADS in terms of biogas productivity when fractionated biocomponents of rice straw were used to achieve a high methane bioconversion rate. A 33.3 % higher methane yield was obtained with the acclimatized consortium (AC) compared to that of ADS control. The dominant pair-wise link between Firmicutes (18.99-40.03 %), Bacteroidota (10.94-28.75 %), and archaeal Halobacteriota (3.59-20.57 %) phyla in the AC seed digesters indicated that the keystone members of these phyla were responsible for higher methane yield. A high abundance of syntrophic bacteria such as Proteiniphilum (1.22-5.19 %), Fermentimonas (0.71-5.31 %), Syntrophomonas (0.87-3.59 %), and their syntrophic partner Methanosarcina (4.26-18.80 %) maintained the digester stability and facilitated higher substrate-to-methane conversion in the AC seed digesters. The present combined strategy will help in boosting the 'biomass-to-methane" conversion.

Efficacious bioconversion of waste walnut shells to xylotetrose and xylopentose by free xylanase (Xy) and MOF immobilized xylanase (Xy-Cu-BTC).

This study uses a cost effective and efficient method for production of higher DP (degree of polymerization) Xylooligosaccharides (XOS) from xylan extracted from the waste walnut shells. Copper based metal organic framework (Cu-BTC MOF) was prepared for immobilization of free xylanase (Xy) enzyme by green synthesis method. Both free and immobilized xylanase (Xy-Cu-BTC) were able to cause the bioconversion of xylan (87.4% yield) into XOS. Predominant production of xylotetrose (X4) and xylopentose (X5) was observed for both the methods. Percentage XOS conversion for free enzyme (Xy) was found to be 4.1% X4 and 60.57% X5 whereas these values increased in case of immobilized system where 11.8% X4 and 64.2% X5 were produced. Xylose production was minute in case of immobilized xylanase 0.88% which makes it a better method for XOS production free from xylose interference. Xy-Cu-BTC MOF can hence be used as an attractive alternative for pure XOS production.

High-throughput integrated pretreatment strategies to convert high-solid loading microalgae into high-concentration biofuels.

The commercial feasibility of energy-efficient conversion of highly concentrated microalgal suspensions to produce high-titer biofuels is a major bottleneck due to high energy consumption. Herein, high-titer biofuels (bioethanol, higher-alcohols, and biodiesel) were generated from carbohydrate-rich Chlamydomonas mexicana and lipid-rich Chlamydomonas pitschmannii biomass through energy-saving microwave pretreatment, successive fermentation, and transesterification. Microwave pretreatment needed low specific energy (4.2 MJ/kg) for 100 g/L of microalgal suspension. Proposed sustainable integrated pretreatments method achieved unprecedented total conversion efficiency (67%) and highest biomass utilization (87%) of C. pitschmannii (100 g/L) with high yields of bioethanol (0.48 g-ethanol/g-carbohydrates), higher-alcohols (0.44 g-higher-alcohols/g-proteins), and biodiesel (0.90 g-biodiesel/g-lipids). Transmission electron microscopy showed the changes in the microalgal cellular integrity before and after sequential fermentations. Energy-efficient integrated pretreatments enhanced the extraction efficiency and whole utilization of high-concentration microalgae to generate high-titer biofuels with minimum waste production.

Roles and applications of enzymes for resistant pollutants removal in wastewater treatment.

Resistant pollutants like oil, grease, pharmaceuticals, pesticides, and plastics in wastewater are difficult to be degraded by traditional activated sludge methods. These pollutants are prevalent, posing a great threat to aquatic environments and organisms since they are toxic, resistant to natural biodegradation, and create other serious problems. As a high-efficiency biocatalyst, enzymes are proposed for the treatment of these resistant pollutants. This review focused on the roles and applications of enzymes in wastewater treatment. It discusses the influence of enzyme types and their sources, enzymatic processes in resistant pollutants remediation, identification and ecotoxicity assay of enzymatic transformation products, and typically employed enzymatic wastewater treatment systems. Perspectives on the major challenges and feasible future research directions of enzyme-based wastewater treatment are also proposed.

Selective carbon sources and salinities enhance enzymes and extracellular polymeric substances extrusion of Chlorella sp. for potential co-metabolism.

This study investigated the extracellular polymeric substance (EPS) and enzyme extrusion of Chlorella sp. using seven carbon sources and two salinities for potential pollutant co-metabolism. Results indicated that the levels of biomass, EPS and enzymes of microalgae cultured with glucose and saccharose outcompeted other carbon sources. For pigment production, glycine received the highest chlorophyll and carotene, up to 10 mg/L. The EPS reached 30 mg/L, having doubled the amount of protein than carbohydrate. For superoxide dismutase and peroxidase enzymes, the highest concentrations were beyond 60 U/ml and 6 nmol/d.ml, respectively. This amount could be potentially used for degrading 40% ciprofloxacin of concentration 2000 µg/L. When increasing salinity from 0.1% to 3.5%, the concentrations of pigment, EPS and enzymes rose 3 to 30 times. These results highlighted that certain carbon sources and salinities could induce Chlorella sp. to produce EPS and enzymes for pollutant co-metabolism and also for revenue-raising potential.

Pretreatment of polysaccharidic wastes with cellulolytic Aspergillus fumigatus for enhanced production of biohythane in a dual-stage process.

Biological pretreatment of polysaccharidic wastes (PWs) is a cost-effective and environmentally friendly approach to improve the digestibility and utilization of these valuable substrates in dual-stage biohythane production. In order to reduce the prolonged incubation time and loss of carbohydrate during the pretreatment of PWs with Aspergillus fumigatus, a systematic optimization using Taguchi methodology resulted in an unprecedented recovery of soluble carbohydrates (362.84 mg g-1) within 5 days. The disruption and fragmentation of lignocellulosic structures in PWs, and possible saccharification of cellulose and hemicellulose components, increased its digestibility. A dual-stage biohythane production with pretreated PWs showed increased yield (214.13 mL g-1 VSadded), which was 56% higher than the corresponding value with the untreated PWs. This resulted in 47% higher energy recovery as biohythane in pretreated biomass compared to untreated biomass. Optimized fungal pretreatment is, therefore, an effective method to improve the digestibility of PWs and its subsequent conversion to biohythane.