Evaluation of Phanerochaete chrysosporium for swine wastewater treatment

Industrial applications of Phanerochaete chrysosporium lignin-degrading enzymes: current status, production challenges, and future directions

Phanerochaete chrysosporium (Pc) is a white-rot fungus recognized for its highly efficient lignin-degrading enzymes (LDEs), including lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase. These oxidative enzymes possess transformative capabilities across multiple industrial applications, such as biopulping, biofuel production, bioremediation and for the treatment of industrial wastewater. However, the commercial use of these enzymes is limited due to time-consuming scale-up procedures in native hosts, instability in industrial environments, and high production costs. The recent developments in recombinant expression systems, particularly those employing microbial and plant platforms provide promising opportunities to enhance enzyme yield, stability, and reduce the cost. Despite these advancements, significant challenges remain, which include the formation of inclusion bodies, the need for nutrient and co-factor supplementation, and the development of effective purification strategies. Modern advancements in protein engineering, such as site-directed mutation and in silico approaches, may hold significant promise in addressing the challenges posed by pH optimization, which is prominent in wild-type enzymes. This review examines the current industrial applications of P. chrysosporium ligninolytic enzymes, highlights production bottlenecks in several hosts, and discusses the strategies to enhance their commercial viability of these enzymes.

Recent advances in swine wastewater treatment technologies for resource recovery: A comprehensive review

Swine wastewater (SW), characterized by highly complex organic and nutrient substances, poses serious impacts on aquatic environment and public health. Furthermore, SW harbors valuable resources that possess substantial economic potential. As such, SW treatment technologies place increased emphasis on resource recycling, while progressively advancing towards energy saving, sustainability, and circular economy principles. This review comprehensively encapsulates the state-of-the-art knowledge for treating SW, including conventional (i.e., constructed wetlands, air stripping and aerobic system) and resource-utilization-based (i.e., anaerobic digestion, membrane separation, anaerobic ammonium oxidation, microbial fuel cells, and microalgal-based system) technologies. Furthermore, this research also elaborates the key factors influencing the SW treatment performance, such as pH, temperature, dissolved oxygen, hydraulic retention time and organic loading rate. The potentials for reutilizing energy, biomass and digestate produced during the SW treatment processes are also summarized. Moreover, the obstacles associated with full-scale implementation, long-term treatment, energy-efficient design, and nutrient recovery of various resource-utilization-based SW treatment technologies are emphasized. In addition, future research prospective, such as prioritization of process optimization, in-depth exploration of microbial mechanisms, enhancement of energy conversion efficiency, and integration of diverse technologies, are highlighted to expand engineering applications and establish a sustainable SW treatment system.

The potential and sustainable strategy for swine wastewater treatment: Resource recovery

Swine wastewater is highly polluted with complex and harmful substances that require effective treatment to minimize environmental damage. There are three commonly used biological technologies for treating swine wastewater: conventional biological technology (CBT), microbial electrochemical technology (MET), and microalgae technology (MT). However, there is a lack of comparison among these technologies and a lack of understanding of their unique advantages and efficient operation strategies. This review aims to compare and contrast the characteristics, influencing factors, improvement methods, and microbial mechanisms of each technology. CBT is cost-effective but has low resource recovery efficiency, while MET and MT have the highest potential for resource recovery. However, all three technologies are affected by various factors and toxic substances such as heavy metals and antibiotics. Improved methods include exogenous/endogenous enhancement, series reactor operation, algal-bacterial symbiosis system construction, etc. Though MET is limited by construction costs, CBT and MT have practical applications. While swine wastewater treatment processes have developed automatic control systems, the application need further promotion. Furthermore, key functional microorganisms involved in CBT's pollutant removal or transformation have been detected, as have related genes. The unique electroactive microbial cooperation mode and symbiotic mode of MET and MT were also revealed, respectively. Importantly, the future research should focus on broadening the scope and scale of engineering applications, preventing and controlling emerging pollutants, improving automated management level, focusing on microbial synergistic metabolism, enhancing resource recovery performance, and building a circular economy based on low-cost and resource utilization.