Liquid Inoculum Research Articles

Enhancing Broccoli growth by bacillus rhizosphere bacteria

This study examines the enhancement of broccoli growth by Bacillus Rhizosphere. Bacteria Broccoli is a nutrient-rich vegetable known for its high content of polyphenols, flavonoids, vitamins, minerals, fiber, and low calorie count, making it a recommended daily food. Tropical regions grow broccoli in mountainous areas. Sustainable agriculture emphasizes minimizing chemical fertilizers, and biofertilizers like Plant Growth Promoting Rhizobacteria (PGPR), such as Bacillus, can reduce their use. Bacillus improves plant growth by fixing nitrogen, solubilizing phosphate and potassium, and producing phytohormones. Understanding Bacillus growth dynamics is vital for optimizing its agricultural application. This study aimed to analyze growth curves of different Bacillus species and investigate their potential role in promoting broccoli growth. This study was carried out in January–April 2024 at the Soil Biology Laboratory, Faculty of Agriculture, Universitas Padjadjaran, and Bumi Agro Technology Company, Lembang. The research was divided into 3 stages: growth curve determination, Bacillus liquid inoculant preparation, and application of treatment to plants. The findings showed that isolates of B. safensis strain MDL5, B. altitudinis strain RPW2, B. subtilis strain YPS4, and Bacillus sp. strain SZ057 reached the highest point in their growth curves after 4 and 5 days of incubation. After that, the curves slowly went down. Inoculating Bacillus into broccoli plants resulted in an increase in plant height by 43.28–58.75% compared to the control.

Optimisation of fermentation condition for production of hight monacolin k (mk) yield by monascus-strains

Monacolin K (MK), produced by Monascus fermentation, has significant hypolipidemic effects. In this study, under solid-state fermentation (SSF) quinoa was used as substrate to investigate the effect of the MK production by Monascus species quinoa. The results of the single factor experiment showed that the amount of the substrate loaded, addition of water to the substrate, and fermentation temperature change time have a significant effect on the MK production of Monascus-fermented quinoa. It was found that neither M. pilosus-fermented quinoa nor M. ruber-fermented quinoa produced citrinin. Consequently, these three factors were selected for the response surface optimization to determine the optimal fermentation process. The results showed that the optimal fermentation process of M. pilosus-fermented quinoa was as follows: quinoa loading amount of 30 g/300 ml, addition of 20 ml water to substrate, seed liquid inoculation volume of 10%, cultured at 30°C for 2 days, followed by a temperature change to 25°C and continued cultivation until 12 days. Under this fermentation process, the yield of MK reached 2.51 mg/g and without production of any citrinin. The optimal fermentation process of M. ruber-fermented quinoa was as follows: quinoa loading amount of 31 g/300 ml, water addition of substrate of 20 ml, seed liquid inoculation volume of 20%, cultured at 30°C for 2 days, followed by a temperature change to 25°C and continued cultivation until 12 days. Under this fermentation process, the yield of MK reached 3.22 mg/g and without any citrinin production. Bangladesh J. Bot. 53(3): 717-729, 2024 (September) Special

Harnessing Bacillus safensis as biofertilizer for sustainable drought alleviation in Brassica juncea L

Carrier-based biofertilizers, which involve the introduction of plant growth-promoting bacteria into agricultural industry waste materials, are gaining increasing attention due to their profoundly positive impacts on soil health. In current study, various carriers, including dry leaves, sugarcane husk (SCH), rice husk (RH), and a combination/Mixture (MIX) of all three, were employed to support the bacterial strain, Bacillus safensis (SCAL1). This strain was utilized as a bioinoculant in the production of carrier-based biofertilizers. This particular strain was sourced from the Environmental and Microbial Botany Lab at Quaid-i-Azam University in Islamabad. Bacillus safensis strain exhibited notable improvements, evident in a high rate of longevity and larger colony-forming units within the carriers, as confirmed by measurements taken after 21 days of incubation. The drought stress was induced using polyethylene glycol solutions with concentrations of 15% and 25% administrated 6 and 15 days after germination, respectively. Four distinct biofertilizer types were formulated in the study: DL + SCAL1, RH + SCAL1, SCH + SCAL1, and MIX + SCAL1. When applied to Brassica juncea L. plants, all of these biofertilizers demonstrated the ability to mitigate drought stress and enhance the quality of Brassica juncea L. The immobilization onto SCAL1 by using SCH showed the best result compared to the liquid inoculum as carrier materials improve stability and shelf life. Furthermore, our results affirmed that carrier-based biofertilizers improved biochemical and physiological attributes of plants during drought conditions, highlighting their importance as a valuable resource for mitigating drought stress in Brassica juncea L. The findings revealed that carrier-based biofertilizers are an excellent source of diverse phytohormones, which are pivotal in alleviating drought stress.

Composting and Liquid Formulations: Panacea to Better Yield in Agriculture: A Review

Liquid formulations, including aqueous, oil, and polymer-based products, often use polysaccharides to alter fluid properties. Liquid inoculants offer cost-effective alternatives to solid carriers, particularly benefiting small producers in India by overcoming transportation and processing challenges. Ideal liquid inoculants are non-toxic, low-cost, uniform, nutrient-supplemented, and support rapid microorganism release and growth. Effective formulations stabilize organisms, ensure easy field delivery, protect against environmental factors, and enhance microbial activity. Rich in nutrients and organic matter, compost enhances the texture, structure, and moisture retention of soil, improving soil qualities and crop productivity. It boosts soil enzyme activity and microbial populations, promoting nitrogen fixation and nutrient availability. Organic manure applications increase soil fertility, water retention, and reduce bulk density. Field and horticultural crops, such as potatoes, chillies, and tomatoes, show significant yield improvements with compost, which also suppresses plant diseases and weed populations. These findings underscore the importance of adopting liquid formulations and composting as sustainable agricultural practices.

Packing Incubation and Addition of Rot Fungi Extracts Improve BTEX Elimination from Air in Biotrickling Filters.

The removal of benzene, toluene, ethylbenzene, and xylene (BTEX) from air was investigated in two similar biotrickling filters (BTFs) packed with polyurethane (PU) foam, differing in terms of inoculation procedure (BTF A was packed with pre-incubated PU discs, and BTF B was inoculated via the continuous recirculation of a liquid inoculum). The effects of white rot fungi enzyme extract addition and system responses to variable VOC loading, liquid trickling patterns, and pH were studied. Positive effects of both packing incubation and enzyme addition on biotrickling filtration performance were identified. BFF A exhibited a shorter start-up period (approximately 20 days) and lower pressure drop (75 ± 6 mm H2O) than BTF B (30 days; 86 ± 5 mm H2O), indicating the superior effects of packing incubation over inoculum circulation during the biotrickling filter start-up. The novel approach of using white rot fungi extracts resulted in fast system recovery and enhanced process performance after the BTF acidification episode. Average BTEX elimination capacities of 28.8 ± 0.4 g/(m3 h) and 23.1 ± 0.4 g/(m3 h) were reached for BTF A and BTF B, respectively. This study presents new strategies for controlling and improving the abatement of BTEX in biotrickling filters.

Growth response of tomatoes to application of bacterial-coated NPK fertilizer in a pot experiment

Nitrogen-fixer and phosphate-solubilizer bacteria increase the chemical-fertilizer efficiency and soil health. Bacterial-coated NPK fertilizer is a novel approach for intensifying biofertilizer application in vegetable production. The study aimed to observe the compatibility between two Azotobacter species and two Bacillus species, their population on two formulations of bacterial-coated NPK fertilizer (BCN), and the effect of BCN dose on growth, N and P content, and their uptake in tomato shoots. The compatibility test was performed using the streak method. The population of Azotobacter and Bacillus were counted for two formulations of NPK fertilizer coated by solid biofertilizer (5% and 10%) and zeolite (1% and 5%). The pot experiment was conducted in a randomized block design with four treatments and six replications. The treatments were 100% recommended doses of conventional NPK fertilizer (700 kg/ha) and 100%, 80%, and 60% doses of BCN. The results showed four bacterial species were compatible, indicated by synergistic growth on the plate agar. The BCN formula using 5% liquid inoculant and 5% zeolite has higher cell viability. The BCN enhanced stem thickness and leaves number but did not change the plant height, dry weight, N and P content, and their uptake in shoots. Applying 60% of BCN caused greater stem thickness and leaf number. Despite being insignificantly different from another treatment, that dose increased the biomass and the shoot uptake of N and P. The NPK fertilizer coated by Azotobacter and Bacillus has the potency to increase tomato growth and NPK fertilizer dose.

Glomus mosseae AND Pseudomonas fluorescens AGAINST Soybean mosaic virus UNDER DRIP IRRIGATION SYSTEM

ARTICLE HIGLIGHTS- Glomus mosseae and Pseudomonas fluorescens enhance soybean resistance to SMV.- Ten-day drip irrigation stop at bloom stage boosts seed yield and weight.- Treatment reduces disease severity and increases P. fluorescens population.- Water-saving irrigation method improves soybean performance in dry seasons.- Combining G. mosseae and P. fluorescens increases soybean productivity. ABSTRACTSoybeans [Glycine max (L.) Merr.] require much water, especially in the early stages of growth, flowering, and pod formation and filling. Drought stress on soybeans will increase with global climate change. The research aimed to evaluate the efficacy of Glomus mosseae and Pseudomonas fluorescens in inducing systemic resistance to control Soybean Mosaic Virus (SMV) and the performance of soybean plants with drip irrigation in the dry season. The drip irrigation was stopped for ten days at the beginning of bloom, full bloom, beginning pod, and regular drip irrigation. The application of G. mosseae inoculants used 100 g of sterile compost mixed with 30 spores. The liquid inoculum of P. fluorescens was applied on cotyledonary leaves using the watering method. The plants were inoculated with SMV 6 and 12 days after the P. fluorescens treatment. The symptoms of SMV were recorded two weeks after inoculation, and Indirect ELISA detected the virus. The results showed the combination of G. mosseae and P. fluorescens under drip irrigation stopped at the beginning of bloom for ten days on ELISA absorbance values and disease severity of 0.259 and 3.72 %, respectively. Moreover, this treatment showed the highest values for the 100-seed weight, seed yield, and fresh weight of leaves. The technique of giving water by stopping drip irrigation at the beginning of bloom for ten days will help save water and increase the P. fluorescens population optimally in Alfisols with a pH of between 4.5 and 5.1 with incredibly low fertility. The combination of G. mosseae and P. fluorescens population resulted in a significant increase in the number of G. mosseae’s spores by stopping drip irrigation at the beginning of bloom for ten days.

Microbiological, sensory, and chemical properties of high-quality tempeh made with instant Mosaccha tempeh inoculum powder.

The combination of Saccharomyces cerevisiae and Rhizopus oligosporus liquid inoculum has been successfully used to ferment soybeans into tempeh that contains β-glucan. However, using the liquid inoculum of these two microbes as a starter is impractical; so, developing an instant tempeh dry inoculum in powdered form, called the Mosaccha inoculum powder, for ease of use is necessary. This study aimed to determine the best concentration of instant Mosaccha inoculum powder to produce high-quality Mosaccha tempeh. The study used a Complete Randomized Block Design with seven different levels of instant Mosaccha inoculum powder percentage, ranging from 0.3% to 1.8% (w/w). A commercial tempeh inoculum, RAPRIMA, amounting to 0.2%, was used as control. Then, the microbiological (total mold and total yeast) and sensory (color, aroma, texture, and taste) properties were evaluated. The data obtained was analyzed statistically using analysis of variance (ANOVA) and Honestly Significant Difference (HSD) tests at the 5% level. The results showed that the percentage of instant Mosaccha inoculum powder significantly affected the microbiological and sensory properties of Mosaccha tempeh. A concentration of Mosaccha inoculum powder between 0.6% to 1.8% could produce good quality Mosaccha tempeh, but the best Mosaccha tempeh was produced with 1.5% instant Mosaccha inoculum powder, which met the Indonesian National Standards (SNI) 3144:2015, had a very favorable taste, and contained 0.49% β-glucan. Therefore, Mosaccha inoculum in powdered form can be developed and used as a starter in making high-quality tempeh that contains β-glucan.

Optimization of fermentation parameters to improve the biosynthesis of selenium nanoparticles by Bacillus licheniformis F1 and its comprehensive application

BackgroundSelenium nanoparticles (SeNPs) are increasingly gaining attention due to its characteristics of low toxicity, high activity, and stability. Additionally, Bacillus licheniformis, as a probiotic, has achieved remarkable research outcomes in diverse fields such as medicine, feed processing, and pesticides, attracting widespread attention. Consequently, evaluating the activity of probiotics and SeNPs is paramount. The utilization of probiotics to synthesize SeNPs, achieving large-scale industrialization, is a current hotspot in the field of SeNPs synthesis and is currently the most promising synthetic method. To minimize production costs and maximize yield of SeNPs, this study selected agricultural by-products that are nutrient-rich, cost-effective, and readily available as culture medium components. This approach not only fulfills industrial production requirements but also mitigates the impact on downstream processes.ResultsThe experimental findings revealed that SeNPs synthesized by B. licheniformis F1 exhibited a spherical morphology with diameters ranging from 110 to 170 nm and demonstrating high stability. Both the secondary metabolites of B. licheniformis F1 and the synthesized SeNPs possessed significant free radical scavenging ability. To provide a more robust foundation for acquiring large quantities of SeNPs via fermentation with B. licheniformis F1, key factors were identified through single-factor experiments and response surface methodology (RSM) include a 2% seed liquid inoculum, a temperature of 37 ℃, and agitation at 180 rpm. Additionally, critical factors during the optimization process were corn powder (11.18 g/L), soybean meal (10.34 g/L), and NaCl (10.68 g/L). Upon validating the optimized conditions and culture medium, B. licheniformis F1 can synthesize nearly 100.00% SeNPs from 5 mmol/L sodium selenite. Subsequently, pilot-scale verification in a 5 L fermentor using the optimized medium resulted in a shortened fermentation time, significantly reducing production costs.ConclusionIn this study, the efficient production of SeNPs by the probiotic B. licheniformis F1 was successfully achieved, leading to a significant reduction in fermentation costs. The exploration of the practical applications of this strain holds significant potential and provides valuable guidance for facilitating the industrial-scale implementation of microbial synthesis of SeNPs.

Bioformulation of mineral solubilizing microbes as novel microbial consortium for the growth promotion of wheat (Triticum aestivum) under the controlled and natural conditions

Microbes are a worthwhile organism of the earth that could be formulated as consortium which can be utilized as biofertilizers. Consortium-based bioinoculants or biofertilizers are superior to single strain-based inoculants for sustainable agricultural productivity and increased micronutrient content in yield. The aim of present study was to evaluate the effect of different combinations of beneficial bacteria that are more effective than single-based bioinoculants. The current work focuses on the isolation of rhizospheric microorganisms from various cereals and pseudocereal crops and the development of a single inoculum as well as a bacterial consortium which were evaluated on wheat crop. A total 214 rhizospheric bacteria were sorted out and, screened for mineral solubilizing attributes i.e., phosphorus, potassium, zinc and selenium solubilization. Among all the bacterial isolates, four potential strains exhibiting P, K, Zn and Se-solubilizing attributes were identified with the help of 16S rRNA gene sequencing as Rahnella aquatilis EU-A3Rb1, Erwinia aphidicola EU-A2RNL1, Brevibacillus brevis EU-C3SK2, and Bacillus mycoides EU-WRSe4, respectively. The identified strains formulated as a consortium which were found to improve the plant growth and physiological parameters in comparison to single culture inoculants and control. To the best of our knowledge, the present investigation is the first report that has developed the consortium from bacterial strains Rahnella aquatilis EU-A3Rb1, Erwinia aphidicola EU-A2RNL1, Brevibacillus brevis EU-C3SK2, and Bacillus mycoides EU-WRSe4. A combination of bacterial strains could be used as liquid inoculants for cereal crops growing in mountainous regions.

Comparative study and characterization of water-treated bacterial cellulose produced by solid or liquid inoculum of Komagateibacter sucrofermentans

Structural and physicochemical properties of two types of bacterial cellulose (BC) produced by Komagateibacter sucrofermentans strain DSM 15973T after 7 days through either immobilized bacteria (solid inoculum) forming BCS7 or free bacteria (liquid inoculum) forming BCL7, followed by a water-based purification as a chem-free alternative treatment, were investigated in this study. SEM verifies the effectiveness of the water-based purification on BC network and reveals the insufficient interfibrillar space of BCS7 compared to BCL7. BCL7 was generally proved to be superior to BCS7 regarding degree of purification, BC yield, overall higher porosity, water swell ability, and water holding capacity (WHC), exhibiting higher hydrophilicity. However, thermally resistant BCS7 reveals a 35% residual up to 800 ºC compared to BCL7 (15%) and prevailed in terms of water retention rate. Both water-treated BC7 were proved to be Iα-rich cellulose type and exhibited a typical type IV(a) isotherm with an H3 type of hysteresis loop, a similar pore distribution, crystallinity index (~77%), crystallite size (~7.5 cm), same levels of moisture content (~98%) and the same poor levels of rehydration after the freeze-drying process. During BCL kinetics in 20 mL of HS medium over 7 days, K. sucrofermentans, 2D pellicle formation was observed until day 3 and then 3D. The highest WHC was obtained on day 4 (116 g water/g cellulose), while the lowest on day 1 (19 g water/g cellulose). Overall, we discussed the preparation and characterization of two different BCs water-treated for purification as an eco-friendly alternative method towards functional, and sustainable application.Graphical

Quantifying response of azospirillum and phosphate solubilizing bacteria liquid inoculants seed treatment on productivity and profitability of kharif grain sorghum (Sorghum bicolor)

A field study was carried out during 2017–19 at Sorghum Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra to assess the effect of liquid bio-fertilizers inoculation over existing powder form inoculants on kharif grain sorghum [Sorghum bicolor (L.) Moench]. The experiment comprised of 6 treatments, viz. no bio-fertilizer control i.e. with RDF alone (T1 ); RDF + Azo. (Azospirillum) + PSB @50 g each/kg seed (T2 ); RDF + Azo. + PSB @2 ml each/kg seed (T3 ); RDF + Azo. @2 ml and PSB @4 ml/kg seed (T4 ); RDF + Azo. @4 ml + PSB @2 ml/kg seed (T5 ); and RDF + Azo. + PSB @4 ml each/kg seed (T6) conducted in randomized block design (RBD) with 4 replications. Pooled data revealed that seed inoculation with Azo. + PSB @2 ml each/kg seed (T3 ) has improved the sorghum biological, grain yield and net returns 21.13, 19.83 and 17.92% over their powder form of inoculants i.e. T2 (14.71 t/ha, 3.56 t/ha and 73,116). These enhancements in biomass, grain yields and net income was owing to liquid bio-fertilizer seed treatment. Liquid-based inoculants were found to boost growth and yield parameters, which was ascribed to the concomitant increase in plant height and number of grains/panicle, respectively. Increase in quantity of liquid bio-fertilizers beyond 2 ml/kg seed proved not-rewarding from both productivity and profitability point of view. Sorghum seed inoculation with liquid bio-fertilizers @2 ml each/kg seed proved to be a potential substitute for existing powder form without any additional cost.

Nata De Coco Quality Development Model from Different Inoculum Sources

The results of the study "Nata De Coco Quality Development Model from Different Inoculum Sources", aim (1) to utilize wasted coconut water from the coconut industry and home industry, (2) to obtain a Nata de Coco quality development model from different inoculum sources (inoculum from pineapple flesh and inoculum that are already available on the market. The methodology used is quantitative (laboratory experiments) with Complete Randomized Design (RAL). This research includes stages, as follows, namely: Phase I, using coconut water media sources with the maturity level of ripe coconuts, with Treatment A = basic ingredients of fresh Coconut Water (0 storage), B = basic ingredients of Coconut Water with storage for 1 week, C = basic ingredients of coconut water with storage for 2 weeks, and treatment D = basic ingredients of coconut water with storage for 3 weeks. Phase II, fermenting coconut water which becomes a substrate as a fermentation medium using inoculum sources, namely: liquid inoculum sources from natural ingredients of pineapple flesh and liquid inoculum sources available on the market in producing cellulose pellicle. The results of the study can be concluded as follows: (1) Coconut water waste wasted from the coconut industry and coconut home industry in the North Minahasa Regency area of North Sulawesi from ripe coconuts can be utilized by Acetobacter xylinum bacteria in producing Nata de Coco pellicle, (2) IN treatment (Natural Acetobacter xylinum liquid inoculum from pineapple fruit) provides the best treatment results from several quality parameters of Nata de Coco produced such as: parameters of Layer Thickness, Water Content, Fiber Content, and Color, than IP treatment (liquid inoculum Acetobacter xylinum on the market).

Fecal microbiota colonization dynamics in dairy heifers associated with early-life rumen microbiota modulation and gut health.

Early-life modulation of rumen microbiota holds promise for enhancing calf growth, health, and long-term production in ruminants. However, limited attention has been given to the impact of rumen microbiota modulation on the establishment of hindgut microbiota. In this study, fecal microbiota development was examined in identical twin calves for 12 months. The treatment group (T-group) received adult cow fresh rumen liquid inoculum during the pre-weaning period, while the control group did not (C-group). The effects of inoculum were assessed on calf gut health and as microbial seeding route into the hindgut. The early rumen modulation had no effect on age-related fecal microbiota development. The fecal bacterial community evolved gradually following dietary changes and categorized into pre-weaning and post-weaning communities. Bacterial richness increased with age and stabilized at month 9, while between-sample variation reduced in post-weaning samples. Archaeal load in fecal samples increased after month 4, while archaeal richness increased and stabilized in both groups by month 9. Between-sample similarity was higher during the pre-weaning period, with increased dissimilarity from month 4 onward. Anaerobic fungi were detected in feces at month 4, with richness peaking at month 7. Before month 6, fungal community composition distinctly differed from mature communities. When colostrum, calf rumen, and donor inoculum were evaluated as seeding sources for hindgut colonization, the calf's own rumen was identified as the primary seeding source for fecal bacteria and fungi. Colostrum was a source for several bacteria detected in feces, but these were of temporary importance until weaning. The donor inoculum had limited impact on gut health as diarrhea rates were similar between the T-group and C-group. In conclusion, early-life microbiota modulation shows potential in ruminant development. However, a more targeted approach with bacteria adapted to the hindgut environment may be necessary to modulate hindgut effectively. This research contributes to our understanding of the complex relationship between gut microbiota and calf health and growth.

Simultaneous Bdellovibrio bacteriovorus–Bacteriophage dosing with SODIS for treatment of environmental water sources

The predatory bacterium Bdellovibrio bacteriovorus HW1 and bacteriophage ABTW1 were applied simultaneously, with solar disinfection (SODIS), for the reduction of Acinetobacter baumannii in environmental water sources. The B. bacteriovorus HW1 and ABTW1 dosing protocol was optimised, with results indicating that the simultaneous application of B. bacteriovorus HW1 and ABTW1 at 0 h resulted in the greatest log reduction (5.66 and 3.97 log based on CFU/mL and GC/mL, respectively) in A. baumannii over the 96 h co-culture period. Similar log reductions (5.24 and 3.85 log reduction based on CFU/mL and GC/mL, respectively) were however, obtained for the initial dosing of B. bacteriovorus at 0 h, and addition of bacteriophage ABTW1 at 24 h. A lyophilised bacteriophage formulation (0.5 M sucrose and 1% gelatine) was then compared to the standard liquid bacteriophage inoculum, with B. bacteriovorus, in upscaled volume trials. However, as similar A. baumannii log reduction results were obtained, the standard bacteriophage liquid inoculum, with B. bacteriovorus, was assessed as a pre-treatment to 6 h SODIS. The B. bacteriovorus HW1-bacteriophage ABTW1 combination as well as the B. bacteriovorus HW1 only pre-treatment, both with SODIS, significantly reduced the A. baumannii cell counts (8.32 and 8.38 log, respectively) to below detection limit (BDL). Molecular analysis however, showed that A. baumannii persisted (∼ 3 log reduction) after the application of all treatment protocols. It is thus recommended that the efficiency of the B. bacteriovorus-bacteriophage combination is further optimised to improve the lytic effect of both biological control agents, particularly the bacteriophage, on their prey.

TRICHO-COMPOSTING OF CROP RESIDUES WITH EASILY PRODUCED T. HARZIANUM LIQUID INOCULUMS

This study aimed to develop a rapid composting method using Trichoderma harzianum culture of liquid state. Assessment of physico-chemical properties and nutritional qualities of composted crop residues generated by Tricho-composting is another concern. Different types of crop residues (Rice straw, Sugarcane bagasse, Black gram straw, and Mustard straw) were composted with T. harzianum IMI 392432 in a randomized block design with three replications. Composting was conducted in cement slabs, maintaining a pH range of 6.55 to 7.40. Temperature peaked at 10°-15°C during thermophilic activity before declining. Moisture content decreased gradually, with 15-20% retained in the finished compost. Weight loss ranged from 40.50% to 51.60%, and decomposition time varied from 67.33 to 96.00 days wherein mustard straw decomposed fast. Sugarcane bagasse decomposed slowly and black gram residues decomposed faster despite having less carbon. Mustard straw exhibited significant weight loss though their carbon content was abundant initially. Despite carbon losses in time, sugarcane bagasse and rice straw retained their properties longer than other residues. The highest phosphorus and potash content found with the decomposed residues of sugarcane in the treatment T2. The treatment of T4 comprise mustard straw showed the lowest phosphorus content and their potash content was 0.19 % which is non-significant with lowest potash containing rice straw generated compost. Easily produced Trichoderma harzianum liquid inoculums accelerated the composting process in accordance with their C:N ratio demonstrating its potential for efficient management of crop residues.

Organic Remobilization of zinc and phosphorus availability to plants by application of mineral solubilizing bacteria Pseudomonas aeruginosa

Incessant utilization of chemical fertilizers leads to the accumulation of minerals in the soil, rendering them unavailable to plants. Unaware of the mineral reserves present in the soil, farming communities employ chemical fertilizers once during each cultivation, a practice that causes elevated levels of insoluble minerals within the soil. The use of biofertilizers on the other hand, reduces the impact of chemical fertilizers through the action of microorganisms in the product, which dissolves minerals and makes them readily available for plant uptake, helping to create a sustainable environment for continuous agricultural production. In the current investigation, a field trial employing Arachis hypogaea L was conducted to evaluate the ability of Pseudomonas aeruginosa to enhance plant growth and development by solubilizing minerals present in the soil (such as zinc and phosphorus). A Randomized Complete Block Design (RCBD) included five different treatments as T1: Un inoculated Control; T2: Seeds treated with a liquid formulation of P. aeruginosa; T3: Seeds treated with a liquid formulation of P. aeruginosa and the soil amended with organic manure (farmyard); T4: Soil amended with organic manure (farmyard) alone; T5: Seeds treated with lignite (solid) based formulation of P. aeruginosa were used for the study. Efficacy was determined based on the plant's morphological characters and mineral contents (Zn and P) of plants and soil. Survival of P. aeruginosa in the field was validated using Antibiotic Intrinsic patterns (AIP). The results indicated that the combination treatment of P. aeruginosa liquid formulation and organic fertilizer (farmyard) (T3) produced the highest biometric parameters and mineral (Zn and P) content of the groundnut plants and the soil. This outcome is likely attributed to the mineral solubilizing capability of P. aeruginosa. Furthermore, the presence of farmyard manure increased the metabolic activity of P. aeruginosa by inducing its heterotrophic activity, leading to higher mineral content in T3 soil compared to other soil treatments. The AIP data confirmed the presence of the applied liquid inoculant by exhibiting a similar intrinsic pattern between the in vitro isolate and the isolate obtained from the fields. In summary, the Zn and P solubilization ability of P. aeruginosa facilitates the conversion of soil-unavailable mineral form into a form accessible to plants. It further proposes the utilization of the liquid formulation of P. aeruginosa as a viable solution to mitigate the challenges linked to solid-based biofertilizers and the reliance on mineral-based chemical fertilizers.

47 Feeding Pigs with Low Crude Protein Diets: Impact of Pig Manure Nitrogen Content on Biogas Production and Digestate Quality

Abstract Lowering dietary crude protein levels is a nutritional strategy recognized to both decrease the use of high-impact feed ingredients and reduce nitrogen (N) excretion. Improved pig manure management practices can further mitigate the environmental impacts associated with pig production towards net-zero emissions. Anaerobic digestion (AD) is a promising technology for transforming pig manure into energy as biogas and into bio-based fertilizers (i.e., digestate from AD). However, little is known about the effects of pig manure N content on AD. Thus, this study aimed to evaluate the impact of pig manure N content on biogas production and digestate quality through the AD of manure from pigs fed low crude protein diets. Three pig manure N concentrations were tested: T1 = 5873, T2 = 5421, and T3 = 5149 total Kjeldahl nitrogen (TKN, mg/L). Throughout 5 sequential fed-batch cycles (25 ± 4 days/cycle), biogas production and its composition (CH4, CO2, and H2S) were measured, while raw manure and weekly digestate samples were analyzed for total solids (TS, %), volatile solids (VS, %), pH, chemical oxygen demand (COD, mg/L), TKN, and ammoniacal nitrogen (NH3-N, mg/L). In a temperature-controlled room (20 ± 1ºC), 6 digesters (3 treatments x 2 replicates) were operated as single-stage reactors to digest pig slurry (mixture of urine and feces, TS: 5.6%) inoculated with a liquid inoculum (TS: 2.3%) to improve manure-microbe interactions. Data were analyzed by ANOVA using PROC MIXED with repeated measures and comparison of means through the Tukey test (SAS software). In addition, both correlation and regression analyses were performed with R to evaluate the relationship among variables. Decreasing pig manure N content showed a tendency to reduce biogas (-20% in T3 vs T1; P = 0.0782) and methane (-22% in T3 vs T1; P = 0.0576) production per cycle, as shown in Table 1. Regarding biogas composition, CH4/biogas and CH4/CO2 decreased with N content (-3 and -4% in T3 vs T1; P ≤ 0.0082). There were strong positive correlations between the N content of pig manure and the amount of NH3-N (linear: r = 0.94, R2 = 0.88) and TKN (linear: r = 0.90, R2 = 0.81) present in the digestate at the end of each cycle. These results suggest that a reduction in pig manure N content reduces biogas production and its quality (ratio of CH4 to CO2). This latter variable is important for biogas efficiency; thus, reducing crude protein in pig diets may impair the production of biogas in AD. However, a decreased N content may cause less emissions into the environment, but when using the digestate as fertilizer, it may not entirely fulfill the N requirements of fast-growing crops for a given application rate.

Two-stage (liquid-solid) anaerobic mono-digestion of ammonia-rich chicken manure at low-temperature: Operational strategy and techno-economic assessment

This study investigated mono-digestion of ammonia-rich chicken manure (CM) in a high-solids anaerobic-digester (HSAD) at low-temperature (20±1°C) adopting the recirculation-percolation mode of operation using liquid-inoculum. HSAD was operated for about 282 days in batch-runs under different organic loading rates (4.3-8.7 gVS/L.d), total solids (65-70%) and total kjeldahl nitrogen (TKN) (23.3- 32.8 g/L) concentrations. It was noted that acclimation of the liquid inoculum to a high concentration of TKN (6.9 g/L) facilitated CM digestion, thereby reducing the start-up phase. The maximum cumulative biogas production rate and specific methane yield were found to be 20 L/d and 0.80±0.12 LCH4g/VSfed, respectively with a methane content over 60% without any signs of inhibition. Operating HSAD at low temperature prevented the accumulation of free-ammonia, which is toxic to methanogens. A techno-economic analysis was also conducted as part of this study to determine the profitability of the system and a 9-year tentative payback period was estimated.

Efficient dose of Bacillus subtilis UFMT-Pant001 as a plant growth promoter in soybean under greenhouse conditions

The potential for increasing soybean productivity and reducing diseases has become evident for Bacillus spp. The objective of this study was to evaluate the efficiency of B. subtilis strain UFMT-Pant001 as a plant growth promoter in soybean under greenhouse conditions. Four independent experiments were conducted in a greenhouse using a B. subtilis UFMT-Pant001 liquid inoculant at 1x109 CFU mL-1. The results showed significant increases in biomass, nodulation, nutrients in the shoot, number of internodes, and root length in soybean cultivars inoculated with B. subtilis UFMT-Pant001 in greenhouse experiments. Positive effects on soybean biomass and other evaluated characteristics were observed with different doses of B. subtilis UFMT-Pant001, with the best results observed when doses of 200 to 300 mL were used for 50 kg of seeds. The use of B. subtilis UFMT-Pant001 did not interfere with soybean nodulation and contributed to an increase in nodule number and weight.