ROS-mediated TCA cycle is greatly related to the UV resistance of Bacillus thuringiensis

Metabolic reprogramming in cancer and senescence

The rising trend in global cancer incidence has caused widespread concern, one of the main reasons being the aging of the global population. Statistical data show that cancer incidence and mortality rates show a clear upward trend with age. Although there is a commonality between dysregulated nutrient sensing, which is one of the main features of aging, and metabolic reprogramming of tumor cells, the specific regulatory relationship is not clear. This manuscript intends to comprehensively analyze the relationship between senescence and tumor metabolic reprogramming; as well as reveal the impact of key factors leading to cellular senescence on tumorigenesis. In addition, this review summarizes the current intervention strategies targeting nutrient sensing pathways, as well as the clinical cases of treating tumors targeting the characteristics of senescence with the existing nanodelivery research strategies. Finally, it also suggests sensible dietary habits for those who wish to combat aging. In conclusion, this review attempts to sort out the link between aging and metabolism and provide new ideas for cancer treatment.

A complex metabolic network and its biomarkers regulate laccase production in white-rot fungus Cerrena unicolor 87613

BACKGROUND

White-rot fungi are known to naturally produce high quantities of laccase, which exhibit commendable stability and catalytic efficiency. However, their laccase production does not meet the demands for industrial-scale applications. To address this limitation, it is crucial to optimize the conditions for laccase production. However, the regulatory mechanisms underlying different conditions remain unclear. This knowledge gap hinders the cost-effective application of laccases.

RESULTS

In this study, we utilized transcriptomic and metabolomic data to investigate a promising laccase producer, Cerrena unicolor 87613, cultivated with fructose as the carbon source. Our comprehensive analysis of differentially expressed genes (DEGs) and differentially abundant metabolites (DAMs) aimed to identify changes in cellular processes that could affect laccase production. As a result, we discovered a complex metabolic network primarily involving carbon metabolism and amino acid metabolism, which exhibited contrasting changes between transcription and metabolic patterns. Within this network, we identified five biomarkers, including succinate, serine, methionine, glutamate and reduced glutathione, that played crucial roles in co-determining laccase production levels.

CONCLUSIONS

Our study proposed a complex metabolic network and identified key biomarkers that determine the production level of laccase in the commercially promising Cerrena unicolor 87613. These findings not only shed light on the regulatory mechanisms of carbon sources in laccase production, but also provide a theoretical foundation for enhancing laccase production through strategic reprogramming of metabolic pathways, especially related to the citrate cycle and specific amino acid metabolism.

Urea Cycle of Bacillus thuringiensis Affects Its Survival under UV Stress

Bacillus thuringiensis (Bt) is widely used to produce biological pesticides. However, its persistence is limited because of ultraviolet (UV) rays. In our previous study, we found that exogenous intermediates of the urea cycle were beneficial to Bt for survival under UV stress. To further explore the effect of the urea cycle on the resistance mechanism of Bt, the rocF/argG gene, encoding arginase and argininosuccinate synthase, respectively, were knocked out and recovered in this study. After the target genes were removed, respectively, the urea cycle in the tested Bt was inhibited to varying degrees. The UV stress test showed that the urea cycle disorder could reduce the resistance of Bt under UV stress. Meanwhile, the antioxidant enzyme activities of Bt were also decreased to varying degrees due to the knockout of the target genes. All of these results revealed that the urea cycle can metabolically regulate the stress resistance of Bt.