Genetically modified entomopathogenic bacteria, recent developments, benefits and impacts: A review.

Entomopathogenic bacteria (EPBs), insect pathogens that produce pest-specific toxins, are environmentally-friendly alternatives to chemical insecticides. However, the most important problem with EPBs application is their limited field stability. Moreover, environmental factors such as solar radiation, leaf temperature, and vapor pressure can affect the pathogenicity of these pathogens and their toxins. Scientists have conducted intensive research to overcome such problems. Genetic engineering has great potential for the development of new engineered entomopathogens with more resistance to adverse environmental factors. Genetically modified entomopathogenic bacteria (GM-EPBs) have many advantages over wild EPBs, such as higher pathogenicity, lower spraying requirements and longer-term persistence. Genetic manipulations have been mostly applied to members of the bacterial genera Bacillus, Lysinibacillus, Pseudomonas, Serratia, Photorhabdus and Xenorhabdus. Although many researchers have found that GM-EPBs can be used safely as plant protection bioproducts, limited attention has been paid to their potential ecological impacts. The main concerns about GM-EPBs and their products are their potential unintended effects on beneficial insects (predators, parasitoids, pollinators, etc.) and rhizospheric bacteria. This review address recent update on the significant role of GM-EPBs in biological control, examining them through different perspectives in an attempt to generate critical discussion and aid in the understanding of their potential ecological impacts.

Antioxidant activities of honeybee products and their mixtures.

In this study, the total phenolic content (TPC), antioxidant activity, and free radical scavenging activities (FRSA) of 70 samples comprising honeybee products (honey, pollen, royal jelly, and propolis) and their mixtures were determined. The TPC was determined in accordance with the Folin-Ciocalteu method, antioxidant activity with phosphomolybdenum, and FRSA with the 1,1-diphenyl-2-picryl hydrazyl (DPPH) assays. Honeybee propolis showed the greatest TPC, antioxidant activity, and FRSA followed by pollen, honey, and royal jelly, respectively. A positive correlation was observed between TPC and antioxidant activity of honey, pollen and mixed samples (respectively, r=0.91, r=0.93 and r=0.92) (p<0.01). Similarly, honey and mixed samples exhibited positive correlations with TPC and FRSA (respectively, r=0.98 and r=0.92) (p<0.01). It was concluded that honeybee products and their mixtures have antioxidant activity and FRSA and these effects may be attributed to their phenolic content.

Effects of honey HMF on enzyme activities and serum biochemical parameters of Wistar rats.

Hydroxymethylfurfural (HMF) is a by-product of thermal degradation of glucose and fructose. In this study, the effects of high HMF content of honey on biochemical parameters of rats were investigated. Experiments were conducted with 40 Wistar albino male rats, each weighing 250-350 g and covered a period of 5 weeks. The animals were divided into five groups. The first group was served as control group. HMF was injected subcutaneously at a dose of 200 mg/kg rat b.w. to the animals in group 2. Group 3 was fed with honey that contains 10 mg HMF/kg honey. In group 4 and 5, there were honeys that contain significantly high HMF content due to long storage period (181 mg HMF/kg honey) and heat process (140 mg HMF/kg honey). At the end of the feeding process, biochemical blood parameters of rats were investigated. It was observed that there were no differences among the glucose, triglyceride, HDL cholesterol, uric acid, Na, GGT, and ALP parameters of the groups. On the other hand, significant differences were observed among the cholesterol, LDL, BUN, creatinine, Ca, P, Mg, K, Cl, total bilirubin, LDH, CPK, AST, ALT, total protein, and pseudocholinesterase values of the rats. The highest adverse effects were obtained from group HMF, and it was followed by groups SH (stored honey) and HH (heated honey). It can be concluded that high HMF content of honey may affect the human health adversely; thus, HMF in honey must be controlled by beekeepers.