RESUMO
Minerals play a dynamic role in plant growth and development. However, most of these mineral nutrients are unavailable to plants due to their presence in fixed forms, which causes significant losses in crop production. An effective strategy to overcome this challenge is using mineral solubilizing bacteria, which can convert insoluble forms of minerals into soluble ones that plants can quickly assimilate, thus enhancing their availability in nutrient-depleted soils. The main objective of the present study was to isolate and characterize mineral solubilizing rhizobacteria and to assess their plant growth-promoting potential for Rhodes grass. Twenty-five rhizobacterial strains were isolated on a nutrient agar medium. They were characterized for solubilization of insoluble minerals (phosphate, potassium, zinc, and manganese), indole acetic acid production, enzymatic activities, and various morphological traits. The selected strains were also evaluated for their potential to promote the growth of Rhodes grass seedlings. Among tested strains, eight strains demonstrated strong qualitative and quantitative solubilization of insoluble phosphate. Strain MS2 reported the highest phosphate solubilization index, phosphate solubilization efficiency, available phosphorus concentration, and reduction in medium pH. Among tested strains, 75% were positive for zinc and manganese solubilization, and 37.5% were positive for potassium solubilization. Strain MS2 demonstrated the highest quantitative manganese solubilization, while strains MS7 and SM4 reported the highest solubilization of zinc and potassium through acidifying their respective media. The strain SM4 demonstrated the most increased IAA production in the presence and absence of L-tryptophan. The majority of strains were positive for various enzymes, including urease, catalase protease, and amylase activities. However, these strains were negative for coagulase activity except strains SM7 and MS7. Based on 16S rRNA gene sequencing, six strains, namely, SM2, SM4, SM5, MS1, MS2, and MS4, were identified as Bacillus cereus, while strains SM7 and MS7 were identified as Staphylococcus saprophyticus and Staphylococcus haemolyticus. These strains significantly improved growth attributes of Rhodes grass, such as root length, shoot length, and root and shoot fresh and dry biomasses compared to the uninoculated control group. The present study highlights the significance of mineral solubilizing and enzyme-producing rhizobacterial strains as potential bioinoculants to enhance Rhodes grass growth under mineral-deficient conditions sustainably.
RESUMO
AIM AND OBJECTIVE: This study was undertaken to compare postoperative sensitivity in posterior class I restorations using etch-and-rinse and self-etch composite resins, GC Fuji IX, and Cention-N. MATERIALS AND METHODS: The sample size consisted of 160 participants. After clinical and radiographic examination, the participants were randomly assigned to four groups consisting of 40 participants each according to the restorative materials used. Class I cavity was prepared and was restored on each patient and after restoration postoperative sensitivity was evaluated at 24 h, 48 h, and 7 days using the visual analog scale (VAS). The results were tabulated and statistically analyzed using analysis of variance (ANOVA) and post-hoc multiple comparison tests. RESULTS: There were significant differences present between the groups at 24 h, 48 h, and 7 days. We found that the materials causing least postoperative sensitivity are ranked according to superiority as GC Fuji IX > nano-hybrid composite using self-etch adhesive > Cention-N > nano-hybrid composite using etch-and-rinse adhesive. CONCLUSION: Both GC Fuji IX and self-etch adhesive showed less postoperative sensitivity as compared to etch-and-rinse and Cention-N at 24 h. With GC Fuji IX and self-etch adhesive postoperative sensitivity was decreased while Cention-N also showed good results at 48 h and 7 days. Etch-and-rinse adhesive showed maximum postoperative sensitivity as compared to other groups at 24 h, 48 h, and 7 days. CLINICAL SIGNIFICANCE: Teeth restored with resin composites are susceptible to sensitivity. The restorative material used and their handling can influence postoperative sensitivity.