Potential of Integrated Use of <i>Bacillus</i> sp. AZ6 and Organic Waste for Zinc Bio-Activation to Improve Physiological Attributes of Maize

Abstract

Zinc (Zn) is an important micronutrient for plant physiology, including the activation of various enzymes, nitrogen metabolism, cell-membrane integrity, and carbonic anhydrase activity. Its deficiency is reported in plants grown in poor soils worldwide including Pakistan. Exogenous application of Zn fertilizers is not efficient due to fixation into the soil. Thus, Zn solubilizing bacteria have a stronger power to chelates the insoluble Zn compounds which may increase Zn availability for plant uptake. Therefore, a pot trial was conducted to evaluate the effects of four products of bio-activated zinc oxide (ZnO) formulated using bio augmented-organic matter coated with zinc oxide (BOZ) on the physiological attributes of maize. Four different products viz. BOZ1, BOZ2, BOZ3, and BOZ4 were prepared using Bacillus sp. AZ6 strain augmented orange peel and ZnO. The results revealed that BOZ4 formulation performed outclass by exhibiting 85%, 31%, and 108% higher photosynthetic rate, stomatal conductance, and transpiration rate, respectively, compared to control. Likewise, it showed a maximum increase in carbonic anhydrase activity, vapor pressure deficit, electrolyte leakage, and SPAD value by 74%, 44%, 45%, and 66%, respectively, over control. Hence, it is concluded that bio-activation of ZnO by Bacillus sp. AZ6 and orange-peel waste could serve as an effective strategy to improve the physiology of maize.

Zinc-Solubilizing Streptomyces spp. as Bioinoculants for Promoting the Growth of Soybean (Glycine max (L.) Merrill)

“…CME34 increased the shoot length, root length, number of pods, number of seeds and plant dry weight by 27.98, 24.09, 45.34, 153.97 and 121.01%, respectively, over the uninoculated control. Our results are consistent with other reports on zinc solubilization to improve plant growth by other bacterial genera [ 15 , 71 ]. The results of this pot experiment were well supported by the results of zinc solubilization assay, whereby Streptomyces was capable of producing organic acids to solubilize insoluble forms of zinc in soil and thus enhanced zinc availability for the plants.…”

Harnessing the Power of Zinc-Solubilizing Bacteria: A Catalyst for a Sustainable Agrosystem

“…Promoted root and shoot length, dry and fresh weight, transpiration rate, and chlorophyll content. [41,42] Table 2. Cont.…”

Effectiveness of Bio-Activated Zinc Coated Urea (Engro Zabardast Urea) for Growth, Yield, and Biochemical Parameters of Rice Crop (Oryza sativa L.)

“…Coating cover of BAZ © and BAC © encapsulates urea prills induce slow N release mechanism, contribute in reducing N losses and enhance N use efficiency. Collectively, Zabardast urea is revolutionary fertilizer suitable to all types of soils, climates, and crops (Hussain et al, 2020).…”

“…Nazir et al (2021) has been observed that this permeated fertilizer would save the labor costs for the application of biofertilizers, urea and zinc individually. Hussain et al (2020) reported the coating of urea with bioactivated ZnO to support cereal yield, physiology and growth of crop. In Pakistan, after wheat the rice crop is the (2 nd ) most important cereal crop and was preferred for Zn biofortification evaluation.…”