Using SDS-PAGE gel fingerprinting to identify soft-bodied wood-boring insect larvae to species

Species Identification of Bovine Bone Marrow from Nonbovine Products Using Multiplex PCR Technology

Bovine bone marrow is traditionally regarded as a highly nutritious food that has been widely used as a medicinal and health food for several decades in China. A large number of adulterated and counterfeit bone marrows from pigs and donkeys have been used in place of bovine bone marrow in commercial products, which are almost identical morphologically between species. Therefore, we explored the feasibility of multiplex PCR technology to differentiate bovine bone marrows from different domestic animals. Three pairs of specific primers for bovine, pig, and donkey were designed according to the conserved sequence in mitochondrial cytochrome b. A modified method was used to extract the genomic DNA from common domestic animals’ bone marrows. The optimal reaction conditions for triple PCR were optimized. A three-fold PCR detection assay was successfully established to identify three species of bovine, pig, and donkey. Three primers have good specificity and high sensitivity. Additionally, the assay sensitivity test confirmed that the extracted DNA concentration was the lowest in bovine bone marrow at 10°pg/μL. The assay also showed 100% specificity. Rapid authentication of bovine bone marrow and differentiation from nonbovine products can be achieved using an improved SDS alkali denaturation method and species-specific PCR assay. Both species-specific PCR methods described in this study can be potentially applied for the quality evaluation of functional food and drug resources.

Optimization of bacterial cytokine protein production by response surface methodology for environmental bioremediation

In natural and engineered systems, most microorganisms would enter a state of dormancy termed as “viable but non-culturable” (VBNC) state when they are exposed to unpredictable environmental stress. One of the major advances in resuscitating from such a state is the discovery of a kind of bacterial cytokine protein called resuscitation-promoting factor (Rpf), which is secreted from Micrococcus luteus. In this study, the optimization of Rpf production was investigated by the response surface methodology (RSM). Results showed that an empirical quadratic model well predicted the Rpf yield, and the highest Rpf protein yield could be obtained at the optimal conditions of 59.56 mg L⁻¹ IPTG, cell density 0.69, induction temperature 20.82 °C and culture time 7.72 h. Importantly, Phyre2 web portal characterized the structure of the Rpf domain to have a shared homology with lysozymes, and the highest lysozyme activity was at pH 5 and 50 °C. This study broadens the knowledge of Rpf production and provided potential strategies to apply Rpf as a bioactivator for environmental bioremediation.

A group of secreted proteins from M. luteus, recognized as resuscitation promoting factors (Rpf) can resuscitate the viable but non-culturable (VBNC) state bacteria which have the potential function of environmental bioremediation.