Recent Advances in Food Nutrition & Agriculture - Volume 15, Issue 3, 2024

Sewage sludge is a by-product of urbanization that poses environmental and health challenges. However, it can also be a valuable source of organic matter and nutrients for agriculture.

This study aimed to assess the potential of five types of organic fertilizers derived from treated Ganga sludge on the growth of wheat plants. The Patanjali Organic Research Institute has developed five types of granulated organic fertilizer from the stabilized Ganga sludge.

The results showed that the organic fertilizers significantly improved the wheat performance in terms of plant height, biomass accumulation, chlorophyll content, leaf area and other yield parameters. Furthermore, the fertilizers ameliorated soil physicochemical attributes and augmented the availability of macro- and micronutrients. Importantly, levels of heavy metals in soil and wheat grains remained within permissible limits, affirming the safety and appropriateness of these fertilizers for wheat cultivation.

This study underscores the efficient utilization of treated Ganga sludge as a valuable organic fertilizer source, proposing a sustainable and ecologically sound approach for sewage sludge management and enhancement of agricultural productivity.

Plant growth-promoting bacteria (PGPR), while generally considered to aid plant growth with the provision of nutrients, can also be used as biocontrol agents for plant pathogens.

The study assessed the protective potential of inoculums and metabolites of plant growth-promoting rhizobacterial strains against bacterial and fungal pathogens on soybean seedlings.

Inoculums and metabolites of 15 rhizobacterial strains were used for the study. Five pathogens (Alternaria sp., Aspergillus niger, Corynespora sp., Fusarium oxysporum and Xanthomonas campestris) were employed for the study. Four experimental setups: treated-only seeds, infected-only seeds, infected then inoculum or metabolite treated seeds, and infected then distilled water-treated seeds.

In the setup infected with Alternaria sp., final germination values of seeds in the presence of the respective inoculums showed no significant variation between the treated only and the infected then treated setup. In the case of seeds infected with Aspergillus niger, higher germination and vigor index values were observed in the treated-only seeds when compared with the infected then-treated seeds. For seeds infected with Corynespora sp., significantly lower germination and vigor index values were observed in the infected then-treated seeds than the treated-only seeds in the presence of the respective inoculums. With regards to setup infected with Fusarium oxysporum, significantly higher final germination and vigor index values were recorded for the treated only seeds when compared with the infected then treated setups. For the Xanthomonas campestris infected seeds, the majority of the infected then metabolite-treated seeds showed significantly lower final germination values when compared with the treated-only seeds.

The study findings were able to establish the efficacy of some bacteria agents against economically important species of plant pathogens.

The present study investigates the effect of conventional and organic farming systems on the nutritional profile of crops. Different crops, namely–millet, sorghum, sesame, mustard, fenugreek, berseem, pea, potato, and onion were cultivated through conventional agriculture in which chemical fertilizers like urea, DAP (Diammonium Phosphate) and pesticides were used and organic farming in which organic fertilizers like seaweed and vermicompost were used.

The experimental study was done on a field in north India from 2019 to 2021 in six different seasons, and the nutrient profile of the crops with respect to macroelements (S, K, Na, P, Ca, Mg) and microelements (B, Cu, Fe, Mn, Zn, Al) was compared.

Macro and microelements were analyzed by Element analyzer and ICP-OES in both types of farming systems. The content of macro, as well as microelements, was found to be significantly higher in all the organically produced crops as compared to the conventionally grown crops.

Significant differences were observed in the macroelement content of organic onion (P- 900 mg/kg, K-2000mg/kg) and organic pea (K 2250 mg/kg) as compared to the content of conventionally grown onion (P-756 mg/kg, K- 1550 mg/kg) and pea (K-2000 mg/kg). Similarly, microelement content in the organic sesame (Fe - 3.12 mg/kg), organic millet (Fe- 2.19 mg/kg), and organic potato (Zn-200 mg/kg) was higher as compared to conventionally grown sesame (Fe 2.05 mg/kg), millet (Fe- 1.56 mg/kg) and potato (Zn 167 mg/kg).

This investigation concludes that crops with optimum nutritional content can be produced through organic farming with minimum input and maximum production.

Bio-cellulose is a type of cellulose that is produced by some particular group of bacteria, for example, Komagataeibacter (previously known as Acetobacter), due to their natural ability to synthesize exopolysaccharide as a byproduct. Gluconacetobacter xylinus is mostly employed for the production of bio-cellulose throughout the world. Therefore, exploring other commonly available strains, such as Komagataeibacter aceti (Acetobacter aceti), is needed for cellulose production.

Bio-cellulose is one of the most reliable biomaterials in the limelight because it is highly pure, crystalline, and biocompatible. Hence, it is necessary to enhance the industrial manufacturing of bio-cellulose with low costs. Different media such as fruit waste, milk whey, coconut water, sugarcane juice, mannitol broth, and H&S (Hestrin and Schramm’s) broth were utilized as a medium for culture growth. Other factors like temperature, pH, and time were also optimized to achieve the highest yield of bio-cellulose. Moreover, after the synthesis of bio-cellulose, its physicochemical and structural properties were evaluated.

The results depicted that the highest yield of bio-cellulose (45.735 mg/mL) was found at 30 °C, pH 5, and on the 7th day of incubation. Though every culture media experimented with synthesized bio-cellulose, the maximum production (90.25 mg/mL) was reported in fruit waste media. The results also indicated that bio-cellulose has high water-holding capacity and moisture content. XRD results showed that bio-cellulose is highly crystalline in nature (54.825% crystallinity). SEM micrograph demonstrated that bio-cellulose exhibited rod-shaped, highly porous fibers. The FTIR results demonstrated characteristic and broad peaks for O-H at 3336.25 cm^-1, which indicated strong O-H bonding. The thermal tests, such as DSC and TGA, indicated that bio-cellulose is a thermally stable material that can withstand temperatures even beyond 500 °C.

The findings demonstrated that the peel of fruits could be utilized as a substrate for synthesizing bio-cellulose by a rather cheap and easily available strain, Komagataeibacter (Acetobacter aceti MTCC 3347). This alternative culture media reduces environmental pollution, promotes economic advantages, and initiates research on sustainable science.

Potato peel is a byproduct of the potato processing industry and a potential source of functional ingredients such as dietary fiber, polyphenols, and prebiotics. However, the bioaccessibility of polyphenols and antioxidants during in vitro digestion as well as prebiotic potential after in vitro digestion of potato peel flour has not been reported.

The study was designed to assess the bioaccessibility of polyphenols and the prebiotic potential of potato peel flour.

In this study, the changes in polyphenol content and antioxidant capacity during different phases of in vitro digestion, including salivary, gastric and intestinal phases were studied. Additionally, an investigation was conducted to evaluate the prebiotic properties of potato peel flour by in vitro fermentation with Lactobacillus acidophilus.

The findings revealed a significant increase in the recovery index for total phenolic content during both gastric (106.90%) and intestinal (102.71%) digestive phases. Furthermore, polyphenols in potato peel flour exhibited high residual intestinal digestibility index values (>90%). The antioxidant capacity increased by >50% during various phases of in vitro digestion. Regarding prebiotic properties, potato peel flour significantly increased L. acidophilus counts and promoted the production of short-chain fatty acids, specifically propionate and butyrate.

This study suggests that potato peel flour has the potential to serve as a functional ingredient or nutraceutical that can enhance health and may help in reducing environmental problems.