Zinc (Zn) deficiency in humans is an emerging global health issue affecting approximately two billion people across the globe. The situation prevails due to the intake of Zn deficient grains and vegetables worldwide. Clinical identification of Zn deficiency in humans remains problematic because the symptoms do not appear until impair the vital organs, such as the gastrointestinal track, central nervous system, immune system, skeletal, and nervous system. Lower Zn body levels are also responsible for multiple physiological disorders, such as apoptosis, organs destruction, DNA injuries, and oxidative damage to the cellular components through reactive oxygen species (ROS). The oxidative damage causes chronic inflammation lead toward several chronic diseases, such as heart diseases, cancers, alcohol-related malady, muscular contraction, and neuro-pathogenesis. The present review focused on the physiological and growth-related changes in humans under Zn deficient conditions, mechanisms adopted by the human body under Zn deficiency for the proper functioning of the body systems, and the importance of nutritional and nutraceutical approaches to overcome Zn deficiency in humans and concluded that the biofortified food is the best source of Zn as compared to the chemical supplementation to avoid their negative impacts on human.

Conventional weed control methods often have environmental impact. The present study was conducted to screen selected accessions of Pseudomonas for both potential biocontrol of Phalaris minor and Avena fatua and potential concurrent growth promotion of wheat. The four Pseudomonas strains (B11, T19, T24, and T75) were found positive for cyanide production, siderophore production, phosphorus solubilization, oxidase activity, catalase activity, and ACC deaminase activity in vitro. These strains were phytotoxic, causing up to 73.3% mortality in the lettuce seedling bioassay. Consortia of compatible Pseudomonas strains increased A. fatua and P. minor seedling mortality up to 50.0% and 56.7%, respectively, and reduced root length up to 73.8% and 53.9%, respectively, as compared with the uninoculated control. Consortia of compatible Pseudomonas strains increased wheat shoot length, root length, fresh biomass, dry biomass, and leaf greenness up to 41.6%, 100%, 79.9%, 81.5%, and 21.1%, respectively, over the uninoculated control. Four of the 11 Pseudomonas consortia tested expressed good weed suppression and wheat growth promotion capacity and deserve further experimentation. The findings from this study may lead to the formulation of bioherbicides that will improve human and environmental health.

Mungbean can successfully be grown in the small slots present in the existing cropping systems that may increase the farmer income and can also restore soil fertility. The inoculation of crop plants with bacterial inoculants has the potential to increase crop productivity even under different soil and climatic conditions. A field experiment was conducted to evaluate the effectiveness of multi-strain biofertilizer prepared through combined use of Rhizobium phaseoli and Pseudomonas fluorescens and Bacillus subtilis for enhancing the growth, nodulation and productivity of ten mungbean genotypes under field conditions, and effect of inoculation on total bacterial DNA (population) in soil. The experiment was laid out in randomized complete block design (RCBD) with factorial arrangements and three replications. Results revealed that inoculation with multistrain biofertilizer increased the nodule numbers, growth, and yield under different mungbean genotypes when compared with their respective uninoculated control. The genotypes showed different productive potentials either with or without inoculation under field conditions. The genotype NCM 2015 yielded more but inoculation was more effective with genotypes NM 17, NM 19 and NCM-252-10 under field conditions of Bahawalpur. Results of 16S rRNA analysis showed a higher number of gene copies in the rhizosphere of inoculated plants of all mungbean genotypes than those of uninoculated plants. Maximum total bacterial population was observed in the rhizosphere of inoculated plants in NM 11 that was significantly better than un-inoculated control plants of the same mungbean line but non-significant when compared with other lines under inoculation. It is concluded that the use of multistrain biofertilizer prepared through combined use of Rhizobium and PGPR strains containing ACC-deaminase could be an effective approach to improve growth, nodulation and yield of mungbean genotypes. The response of different genotypes to the inoculation varied significantly. So, research for the development of inoculum for different advanced genotypes should be continued and more emphasis should be deployed to develop biofertilizers with efficient strains to use them under different climate and soil conditions.

Untreated wastewater used for irrigating crops is the major source of toxic heavy metals and other pollutants in soils. These heavy metals affect plant growth and deteriorate the quality of edible parts of growing plants. Phytohormone (IAA) and exopolysaccharides (EPS) producing plant growth-promoting rhizobacteria can reduce the toxicity of metals by stabilizing them in soil. The present experiment was conducted to evaluate the IAA and EPS-producing rhizobacterial strains for improving growth, physiology, and antioxidant activity of Brassica juncea (L.) under Cd-stress. Results showed that Cd-stress significantly decreased the growth and physiological parameters of mustard plants. Inoculation with Cd-tolerant, IAA and EPS-producing rhizobacterial strains, however, significantly retrieved the inhibitory effects of Cd-stress on mustard growth, and physiology by up regulating antioxidant enzyme activities. Higher Cd accumulation and proline content was observed in the roots and shoot tissues upon Cd-stress in mustard plants while reduced proline and Cd accumulation was recorded upon rhizobacterial strains inoculation. Maximum decrease in proline contents (12.4%) and Cd concentration in root (26.9%) and shoot (29%) in comparison to control plants was observed due to inoculation with Bacillus safensis strain FN13. The activity of antioxidant enzymes was increased due to Cd-stress; however, the inoculation with Cd-tolerant, IAA-producing rhizobacterial strains showed a non-significant impact in the case of the activity of superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) in Brassica juncea (L.) plants under Cd-stress. Overall, Bacillus safensis strain FN13 was the most effective strain in improving the Brassica juncea (L.) growth and physiology under Cd-stress. It can be concluded, as the strain FN13 is a potential phytostabilizing biofertilizer for heavy metal contaminated soils, that it can be recommended to induce Cd-stress tolerance in crop plants.

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Long-term use of chemical fertilizers is affecting the environment, soil quality, and biodiversity. Organic agriculture is gaining global attention by using microbial-based biofertilizers. Carriers protect microbes by providing nutrition, energy, and suitable conditions for their survival while entering the natural environments. The purpose of this study was to evaluate the ability of different carrier materials to enhance the yield and the quality of spinach and to select the best carrier material for spinach biofertilizer. Three pre-isolated and characterized bacterial strains (AN-35, ZM-27, and ZM-63) were tested for their compatibility and used in this experiment through seed inoculation with organic carriers, i.e., compost, peat, press mud, biochar, and charcoal. A pot experiment and a field experiment were conducted to evaluate the efficacy of different organic carriers. The results of the pot study showed a significant increase in spinach growth, i.e., shoot length (25%), shoot fresh weight (24%), root length (25%), and root fresh weight (29%), spinach nutrition, i.e., nitrogen (18%), phosphorus (22%), potassium (15%), iron (17%), and zinc (14%), spinach physiology, i.e., relative water content (27%), chlorophyll content (9%), and the membrane stability index (28%) under peat coated treatments with 24% more soil microbial populations compared to the control. Similarly, in the field experiment, peat coating significantly enhanced spinach growth, i.e., shoot length (29%), shoot fresh weight (23%), root length (16%), and root fresh weight (24.7%), spinach nutrition, i.e., nitrogen (16%), phosphorus (19%), potassium (15%), iron (17%), and zinc (23%), spinach physiology, i.e., relative water content (28%), chlorophyll content (13%) and the membrane stability index (32%), and spinach yield per hectare (30%), as well as producing 20% higher soil microbial populations. From these results, it is concluded that peat is a good carrier material for biofertilizer production as it not only enhances crop production but also the microbial number, in addition to improving soil quality.

Chemical weed control is an effective method, but has proved hazardous for humans, environment, and soil biodiversity. Use of allelopathic bacteria (AB), may be more efficient and sustainable weed control measure. The bacterial inoculants never studied in context of their interaction with weed root exudates and precursor-dependent production of the natural phytotoxins (cyanide, cytolytic enzymes and auxin) by these stains to understand their weed suppression and wheat growth promotion abilities. Therefore, root exudates of Avena fatua, Phalaris minor, Rumex dentatus and wheat were quantified and their role in microbial root colonization and secondary metabolites production i.e. cyanide, cytolitic enzymes, phenolics and elevated auxin concentration was studied. The results depicted L-tryptophan and glycine as major contributor of elevated cyanide and elevated levels in weed rhizosphere by the studied Pseudomonas strains, through their higher root colonization ability in weeds as compared to wheat. Furthermore, the higher root colonization also enhanced p-coumaric acid (photosynthesis inhibitor by impairing cytochrome c oxidase activity in plants), and cytolytic enzymes (root cell wall degradation) concentration in weed rhizosphere. In conclusion, the differential root colonization of wheat and weeds by these strains is responsible for enhancing weed suppression (enhancing phytotoxic effect) and wheat growth promotion (lowering phytotoxic effect).

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