Biomineralization processes utilizing microbial-induced carbonate precipitation (MICP) have recently shown promise as an effective approach for remediating heavy metal contamination. This article offers a comprehensive review of the latest research on MICP-mediated heavy metal remediation, with a focus on the characteristics of heavy metals in the treated environment, such as copper, cadmium, lead, nickel, zinc, chromium, and mixed heavy metals. The review summarizes experimental results from various heavy metals treated by MICP, including the enrichment and screening of new urease-positive bacteria, the mineral structure of different heavy metal precipitates, and the efficiency of the MICP technology. Recent advancements in the MICP technology regarding heavy metal removal, long-term stability, and practical applications are also discussed. Additionally, the limitations of the technique and existing solutions are reviewed. In addition, it provides insights on future directions for further research and development of the MICP approach for heavy metal remediation, in order to optimize the technique and improve its efficiency. Overall, the review highlights the potential of MICP as a viable method for heavy metal remediation, offering promising results for the removal of a variety of heavy metal contaminants from contaminated environments.

Soil degradation and pollution pose significant threats to global agricultural sustainability and food security. Conventional remediation methods are often constrained by low efficiency, high cost, and potential secondary pollution. Nanobiotechnology, an emerging interdisciplinary field, offers innovative solutions by integrating functional nanomaterials with plant–microbe interactions to advance soil remediation and sustainable agriculture. This review systematically elaborates on the mechanisms and applications of nanomaterials in soil remediation and enhanced plant stress resilience. For contaminant removal, nanomaterials such as nano-zero-valent iron (nZVI) and carbon nanotubes effectively immobilize or degrade heavy metals and organic pollutants through adsorption, catalysis, and other reactive mechanisms. In agriculture, nanofertilizers facilitate the regulated release of nutrients, thereby markedly enhancing nutrient use efficiency. Concurrently, certain nanoparticles mitigate a range of abiotic stresses—such as drought, salinity, and heavy metal toxicity—through the regulation of phytohormone balance, augmentation of photosynthetic performance, and reinforcement of antioxidant defenses. However, concerns regarding the environmental behavior, ecotoxicity, and long-term safety of nanomaterials remain. Future research should prioritize the development of smart, responsive nanosystems, elucidate the complex interactions among nanomaterials, plants, and microbes, and establish comprehensive life-cycle assessment and standardized risk evaluation frameworks. These efforts are essential to ensuring the safe and scalable application of nanobiotechnology in environmental remediation and green agriculture.

The inherent complexity of cellulose, hemicellulose, and lignin contributes to the recalcitrance of lignocellulosic biomass, resulting in a low conversion efficiency and high cost of bioethanol conversion. Pretreatment methods that disrupt the plant cell structure of lignocellulose, such as straw, can significantly enhance the conversion efficiency. In this study, we utilized an acid-assisted mechanocatalytic depolymerization technique to pretreat rice straw, and the results demonstrated a significant disruption of the cellulose structure of the straw. Compared to the untreated straw, the particle size of pretreated straw reduced from 279 μm to 11.8 μm, the crystallinity of cellulose decreased from 43.05% to 22.71%, the specific surface area increased by 177%, and the surface oxygen-to-carbon ratio (O/C) ratio was enhanced by 75%. The changes in microstructure enabled the pretreated straw to achieve a total sugar yield of over 95% within 12 h of enzymatic hydrolysis, significantly superior to the 36.24% yield from untreated straw, the 45.20% yield from acid impregnated straw, and the 73.25% yield from ball milled straw. Consequently, acid-assisted mechanocatalytic depolymerization emerges as a highly effective pretreatment strategy to enhance both the enzymatic hydrolysis and the overall conversion efficiency of rice straw.