In this study, magnetic biochar (MAB) and humic acid (HA)-coated magnetic biochar produced from apple branches without and after cellulase hydrolysis (HMAB and CHMAB, respectively) were prepared and tested as adsorbents of enrofloxacin (ENR) and moxifloxacin (MFX) in aqueous solution. Compared with MAB and HMAB, novel adsorbent CHMAB possessed a superior mesoporous structure, greater graphitization degree and abundant functional groups. When antibiotic solutions ranged from 2 to 20 mg L⁻¹, the theoretical maximum adsorption capacities of CHMAB for ENR and MFX were 48.3 and 61.5 mg g⁻¹ at 35 °C with adsorbent dosage of 0.4 g L⁻¹, respectively, while those of MAB and HMAB were 39.6 and 54.4 mg g⁻¹, and 44.7 and 59.0 mg g⁻¹, respectively. The pseudo-second-order kinetic model and Langmuir model presented a better fitting to the spontaneous and endothermic adsorption process. The maximum adsorption capacity of ENR and MFX onto CHMAB was achieved at initial pH values of 5 and 8, respectively. Additionally, the adsorption capacity of ENR and MFX decreased with increasing concentrations of K⁺ and Ca²⁺ (0.02–0.1 mol L⁻¹). Synergism between the pore-filling effect, π-π electron-donor-acceptor interactions, regular and negative charge-assisted H-bonding, surface complexation, electrostatic interactions and hydrophobic interactions may dominate the adsorption process. This study demonstrated that a novel magnetic biochar composite prepared through pyrolysis of agricultural waste lignocellulose hydrolyzed by cellulase in combination with HA coating was a promising adsorbent for eliminating quinolone antibiotics from aqueous media.

Atrazine has been used on Chinese farmlands for a long time and over a wide range. The concentration of atrazine (1.86–1100 mg kg⁻¹) has exceeded the allowable limit in the soil (1.0 mg kg⁻¹), and concern is increasing about the potential harm to farmland soil. Four treatments (AT₀, AT₆, AT₁₀, AT₁₆) were established to reveal the effects of the long-term application of atrazine on soil health. The results showed a nonlinear regulation of the atrazine residue concentrations in the four treatments. The highest concentration of atrazine residue was in AT₆, at 167 mg kg⁻¹, and the lowest concentration of atrazine residue was in AT₁₆, at 102 mg kg⁻¹, but there was no significant difference between AT₁₀ and AT₁₆. The soil urease activity decreased significantly with the increase in the years of atrazine application, the saccharase and cellulase activities in the AT₆ were significantly higher than those observed in the other three treatments, the catalase activity gradually decreased with the increase in atrazine application years, and the activity in AT₆ was significantly higher than that in AT₁₆. A total of 238 genera were identified by Illumina MiSeq sequencing, and 28 dominant genera were screened. Atrazine significantly increased the relative abundance of Actinobacteria and contributed to the relative abundance of Rubrobacter, Blastococcus, Promicromonospora, Jiangella, Psychroglaciecola and Acetobacteraceae_uncultured, which exhibited significantly higher abundance in AT₁₆ than in AT₀. Although there were atrazine-degrading bacteria in the soil, and the atrazine residue decreased with the increase in application years, the concentration of the atrazine residue was still nearly 100 times higher than the allowable limit in the soil, which is a great threat to the soil health.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | International audience | The feeding activity and subsequent assimilation of the products resulting from food digestion allow organisms to obtain energy for growth, maintenance and reproduction. Among these biological parameters, we studied digestive enzymes (amylase, cellulase and trypsin) in Gammarus fossarum to assess the impact of contaminants on their access to energy resources. However, to enable objective assessment of a toxic effect of decreased water quality on an organisms’ digestive capacity, it is necessary to establish reference values based on its natural variability as a function of changing biotic and abiotic factors. To limit the confounding influence of biotic factors, a caging approach with calibrated male organisms from the same population was used. This study applied an in situ deployment at 23 sites of the Rhone basin rivers, complemented by a laboratory experiment assessing the influence of two abiotic factors (temperature and conductivity). The results showed a small effect of conductivity on cellulase activity and a significant effect of temperature on digestive enzyme activity but only at the lowest temperature (7 °C). The experimental conditions allowed us to define an environmental reference value for digestive enzyme activities to select sites where the quality of the water impacted the digestive capacity of the organisms. In addition to the feeding rate, this study showed the relevance of digestive enzymes as biomarkers to be used as an early warning tool to reflect organisms’ health and the chemical quality of aquatic ecosystems.

Increased solid waste pollution and the negative effect of fossil fuel consumption on the environment are issues that would require more scientific attention and application to deal effectively with these phenomena. Wastepaper, a major component of solid waste, is classified as organic waste due to the presence of cellulose, a glucose-based biopolymer that is part of its structural composition. The saccharification of cellulose into glucose, a fermentable sugar, can be achieved with a hydrolytic enzyme known as cellulase. Although cellulase from fungal species such as Trichoderma, Aspergillus, and Penicillium are well described, knowledge about cellulase isolated from the brown garden snail is limited as it has not been the subject of many research endeavors. The waste paper has been described as a suitable resource for bio-energy development due to cellulose, a structural component of this bio-material that can be degraded into glucose, a fermentable sugar. Although paper materials such as newspaper, office paper, filter paper, Woolworths and Pick and Pay (retailers) advertising paper, as well as foolscap paper, were saccharified by different cellulases, the degradation of these paper materials by garden snail cellulase is a novel investigation from our laboratory. With the effects of temperature and incubation time on this cellulase action when degraded paper materials have already been investigated and reported, this study dealt with the garden snail cellulase action when degraded paper materials at different pH values. Most of the paper materials were degraded optimally at a pH value of 6.0, while optimum saccharification was observed at pH 4.5 when newspaper and brown envelope paper were degraded, with office paper showing maximum bioconversion at pH 7.0. The difference in the structural composition of the paper materials also affects the degree of saccharification, as the amount of sugar released from the various paper materials at optimum pH values is not similar. Together with other catalytic parameters, the pH value of this enzymatic catalysis is also to be considered when designing the development of waste paper as a bio-product resource, with limiting environmental pollution as an additional advantage of this process.

The uncontrolled production of waste is a daily phenomenon that is experienced by most global communities, and the situation worsens due to the lack of effective waste management procedures. Solid waste such as sawdust is primarily produced by the forestry industry and although it is utilized by certain countries as briquettes to make fire or as an absorbent to clean fluid spillage as well as a component of ceilings, most of the sawdust along the Lagos Lagoon in Nigeria is left unattended as waste, contributing to environmental pollution. Cellulose, composed of glucose units is a structural component of sawdust and when saccharified the resulting glucose can be fermented into renewable substances such as bio-ethanol. The cellulose degradation process can be performed with a cellulase enzyme such as available in the fungus Aspergillus niger and during the current investigation, this enzyme system was used to bio-convert the cellulose component of sawdust from ten different trees along the Lagoon into glucose. To increase the cellulase action all sawdust materials were delignified before cellulase action with the main aim of determining the optimum pH value for maximum degradation of the various sawdust materials. The pH-related saccharification profile of each type of sawdust was constructed as well as the relative percentage of saccharification and it was concluded that all the materials were optimum degraded at acidic pH-values which varied between pH 5.0 and pH 6.0 that are like optimum pH-values reported for the other types of cellulose materials.

To expand the range of soluble carbon sources for enzyme production by the microbial system, we investigated the ability of different sugars in cellulase production. Carbon sources play a vital role in cell metabolism and the synthesis of cellulase. Although the insoluble cellulosic materials are considered the most effective natural inducers for cellulase production by microorganisms in terms of both enzyme yield and productivity, their insolubility causes many problems and presents a major drawback that is partly responsible for the high cost of cellulase production. Mostly, the insolubility of sugar polymer leads to difficult and complex fermentation operations, including sterilization, cell biomass measurement, mixing and aeration of the fermentation broth, continuous feeding/sampling, and subsequent enzyme purification. Second, cellulase gets absorbed into the solid cellulose surface, leading to enzyme loss. The present paper gives a comparative view on the utility of pure sugars (lactose, CMC, sucrose, maltose, cellobiose, xylose, trehalose, arabinose) and sugar alcohols (sorbitol, mannitol) on cellulase production by various fungal strains. It also describes the blending effect of sugars as well as sugar alcohols on cellulase production by fungal strains.

Sawdust, a major waste product of the forestry industry, is accumulating along the Lagos Lagoon in Lagos, Nigeria, without it being effectively managed. Besides its use in The saccharification of sawdust could contribute to the development of renewable energy sources and feedstock for bioproduct development. The process is, however, not that straightforward as variables such as the type of cellulase enzyme, pretreatment of the cellulose substrate, and optimizing of cellulase to cellulose ratio are a few that need to be optimized for the process to be effective in terms of glucose production.manufacturing sound-absorbing boards to reinforce concrete beams and for energy purposes, its potential as a renewable energy source and feedstock for bio-product development has not yet been realized. Cellulose, a glucose biopolymer and structural component of cellulose can be hydrolyzed by a hydrolytic enzyme known as cellulase. During the process, the enzyme breaks the B-1,4-glucosidic bond, which keeps the glucose units together, and by acting on this bond, numerous glucose units are released. As part of sawdust, the cellulose molecule is not freely available for the degradation action of the cellulase enzyme as it is strongly associated with lignin, which acts as bio-glue, keeping cellulose and hemicellulose together. Delignification is an effective technique that was used to make the sawdust from ten different trees along the Lagos Lagoon in Nigeria more susceptible to saccharification by cellulase isolated from the fungus Aspergillus niger. Delignified and non-delignified sawdust masses between 2 mg and 10 mg were incubated with the A. niger cellulase solution (2 mg.mL-1), whereafter, the amount of sugar produced by the cellulase action was determined. The percentage saccharification of each sawdust material was also linked with the amount of sugar produced during cellulase action. From these investigations was concluded that delignification increased sugar production when almost all the masses of different sawdust materials were degraded. It was also observed that the ratio of sawdust mass to enzyme concentration is an important variable that influences the effectiveness of the saccharification process. The percentage saccharification of the various sawdust materials was also determined, and it indicated that the highest percentage of saccharification was not obtained when the highest amount of sawdust was degraded, producing the highest amount of sugar.

Sawdust, a product of the forest industry is mostly left untreated as solid waste. This phenomenon is well observed along the Lagos Lagoon in Nigeria where hundreds of trees are cut daily by sawmills to deliver wood for mainly the furniture industry. Different types of trees are utilized in this manner and the massive amounts of sawdust produced as a result of these activities are polluting the environment causing health risks for humans and animals. Cellulose, a glucose bio-polymer is a major structural component of sawdust and could be developed as a renewable energy resource should the cellulose be degraded into glucose, a fermentable sugar. This saccharification was done with Aspergillus niger cellulase and to make the cellulose more susceptible for cellulase action the sawdust was delignified with hydrogen peroxide. Both delignified and non-delignified sawdust were treated with the cellulase enzyme at incubation temperatures of 30°C, 40°C, 50°C, and 60°C. Delignification proved to be effective as an increased amount of sugar was released from all delignified sawdust materials relative to the non-delignified materials when saccharified with A. niger cellulase. Most of the materials were degraded at an incubation temperature of 40°C and 50°C and the highest percentage saccharification of 58% was obtained during the degradation of delignifed cellulose from the tree, Ricindendron heudelotti

The aim of this study was to evaluate the toxicological responses of earthworm (Eisenia fetida) induced by field-contaminated, metal-polluted soils. Biochemical responses and DNA damage of earthworm exposed to two multi-metal-contaminated soils in a steel industry park and a natural reference soil in Zijin Mountain for 2, 7, 14, and 28 days were studied. Results showed that three enzyme activities, including superoxide dismutase (SOD), acetylcholinesterase (AChE), and cellulase, in earthworm in metal-contaminated soils were significantly different from those of the reference soil. Cellulase and AChE were more sensitive than SOD to soil contamination. The Olive tail moment of the comet assay after 2-day exposure increased 56.5 and 552.0 % in two contaminated soils, respectively, compared to the reference soil. Our findings show that cellulase and DNA damage levels can be used as potential biomarkers for exposure of earthworm to metal-polluted soils.