Effect Of Microbial Inoculation Research Articles

Isolation, Characterization and Phylogenetic Analysis of Nodule-Associated Bacteria from Mimosa Pudica L.

The interaction between rhizobia and other nodule-associated bacteria assists to mitigate nutrient stress in leguminous plants by fixing atmospheric nitrogen and synthesizing plant growth regulators. The beneficial effects of microbial inoculants emphasize the need for further research and their use in modern agriculture. The present study describes the isolation, molecular identification, characterization, and phylogenetic analysis of noduleassociated bacteria from Mimosa pudica Linnaeus. Isolation and phenotypic characterization of nodule-associated bacteria were carried out according to standard procedures. Molecular characterization of the isolates was performed using 16S ribosomal RNA. Plant growth promoting the ability of selected isolates was analyzed by assessing indole acetic acid production, nitrogenfixing ability and organic acid production. Evolutionary distance and relatedness were analyzed using the neighbor-joining method. Thirteen nodule-associated bacteria were isolated and identified using 16S rRNA gene sequencing. The selected isolates such as Rhizobium sp. CU8 and three other co-resident non-rhizobial nodule-associated bacteria (Bacillus cereus MY5, Ralstonia pickettii MY1 and Lactococcus lactis MY3) exhibited plant growth promotion and other potential microbial activities. Phylogenetic analysis revealed the genetic relatedness and evolutionary significance of all the thirteen isolates reside in the root nodule of M. pudica. The present study identified four isolates with plant growth promoting properties. L. lactis MY3 is the first report as a co-resident plant growth promoter from the root nodules of M. pudica.

Effect of microbial inoculation and storage length on the fermentation profile and nutritive value of high-moisture corn ensiled at 2 different dry matter concentrations.

The objective of this experiment was to evaluate the effect of microbial inoculation and storage length on the fermentation profile and nutrient composition of high-moisture corn (HMC) ensiled at 2 different dry matter (DM) concentrations. High-moisture corn was harvested when kernel DM concentrations were approaching 65% as-fed, and either left undried (HMC65; 67.6% DM) or dried at 40 °C to approximately 70% DM (HMC70; 71.0% DM), and then ensiled in quadruplicate vacuum pouches untreated (CON) or after one of the following inoculant treatments: 6.36 × 105 cfu of Lentilactobacillus buchneri DSM 12856, Lactiplantibacillus plantarum DSM 12836, and Pediococcus acidilactici DSM 16243 per g of HMC (LBLP); or 3.0 × 105 cfu of Lentilactobacillus buchneri DSM 12856, Lentilactobacillus diolivorans DSM 32074, and P. acidilactici DSM 16243 per g of HMC (LBLD). Vacuum pouches were allowed to ferment for 7, 14, 28, or 56 d. A three-way interaction was observed (P = 0.01) for the pH of HMC, where CON for HMC70 was greatest across storage lengths and HMC65 treatments generally had a lower pH than other treatments. Concentrations of total acids were greater (P = 0.001) in HMC65 than HMC70 and greater (P = 0.001) in HMC treated with LBLP and LBLD than CON. An interaction between DM concentration, microbial inoculation, and storage length was observed (P = 0.05) for concentrations of acetic acid. At 14 d, acetic acid concentrations were greater in HMC65 treated with LBLD than other treatments. Likewise, at 56 d, concentrations of acetic acid were greatest in HMC65 treated with LBLD, followed by HMC70 treated with LBLD. An interaction between DM concentration, microbial inoculation, and storage length was observed (P = 0.05) for 7-h starch disappearance (starchD). Across all DM concentration and inoculant treatment combinations, starchD increased with increasing storage length. StarchD was also generally greater for HMC65 treatments compared to HMC70, with small differences among inoculants. Results suggest that microbial inoculation can improve fermentation of HMC by increasing the production of antifungal acetic acid, but that DM concentration at ensiling remains a primary determinant of HMC fermentability.

Microbial Community, Fermentation Quality, and in vitro Degradability of Ensiling Caragana With Lactic Acid Bacteria and Rice Bran.

This study aimed to assess the effects of microbial inoculants and growth stage on fermentation quality, microbial community, and in vitro degradability of Caragana silage from different varieties. Caragana intermedia (CI) and Caragana korshinskii (CK) harvested at the budding (BU) and blooming (BL) stages were used as raw materials to prepare silage, respectively. The silages at each growth stage were treated for ensiling alone (control), with 5% rice bran (RB), a combination of RB with commercial Lactobacillus plantarum (RB + LP), and a combination of RB with a selected strain Lactobacillus plantarum L694 (RB + L694). The results showed that the crude protein (CP) content of CI was higher than that of CK, and delay in harvest resulted in greater CP content in Caragana at BL stage. After 60 days of fermentation, the concentrations of lactic acid (LA) in the RB + L694 treatments were higher than those in control treatments (p < 0.05), while the pH, concentrations of NH3-N, neutral detergent fiber with the addition of α-amylase (aNDF) were lower than those in control treatments (p < 0.05). RB + L694 treatments could decrease acid detergent fiber (ADF) content except in CIBL. In CK silages, adding RB + L694 could reduce bacterial diversity and richness (p < 0.05). Compared with the control, RB + L694 treatment contained higher Lactobacillus and Enterobacter (p < 0.05). In vitro NDF and DM degradability (IVNDFD and IVDMD) was mostly affected by growth period, and additive RB + l694 treatment had higher IVDMD and lower IVNDFD than other treatments (p < 0.05). Consequently, the varieties, growth stages, and additives could influence the fermentation process, while the blooming stage should be selected in both Caragana. Furthermore, the results showed that RB and L. plantarum could exert a positive effect on fermentation quality of Caragana silage by shifting bacterial community composition, and RB + L694 treatments outperformed other additives.

Effects of Microbial Inoculants on Fermentation Quality and Aerobic Stability of Paper Mulberry Silages Prepared with Molasses or Cellulase

Paper mulberry (Broussonetia papyrifera L.) is an unconventional forage with high crude protein content and is widely used in China. In order to evaluate the pattern of fermentation quality and the aerobic stability when inoculated with lactic acid bacteria, laboratory-scale silage was prepared. The experimental groups included a control group (CK), a Lactobacillus plantarum ‘LC365283’ (selected from paper mulberry silage) treatment (L1), a commercial inoculant Lactobacillus plantarum treatment (GF), a commercial inoculant Lactobacillus buchneri treatment (FR), a 3% molasses treatment (MO), a 150 U/g cellulase treatment (CE), and their combinations (MO + L1, MO + GF, MO + FR, CE + L1, CE + GF, and CE + FR). The changes in bacterial community and composition of the fermentation products were evaluated after being ensiled for 30 days and unsealed for 1, 3, 5, and 7 days. Compared with the CK, MO and CE, the silages treated with L1, MO + L1, and CE + L1 showed higher lactic acid concentrations, lower pH values, and lower ammonia nitrogen concentrations (p &lt; 0.05). During the first 3 days of aerobic exposure, the pH values and organic acid content changed slightly in all treatments. The present study suggests that addition of L1 was better than commercial inoculum, and the paper mulberry silages could be well preserved after being unsealed for 3 days.

Effects of Microbial Inoculation with Different Indigenous Bacillus Species on Physicochemical Characteristics and Bacterial Succession during Short-Term Composting

Bacillus accelerates lignocellulose degradation, promotes the stabilization and resource utilization of compost by secreting enzymes, and plays an important role in compost formation and quality control. This study evaluated enzyme activity, lignocellulosic degradation, and bacterial succession in composting inoculated with different microbial Bacillus agents. They were identified as B. licheniformis, B. subtilis, B. thermoamylovorans, B. thermoruber, and B. hisashii. Four treatments were established, including a CK (uninoculated microorganisms), A (B. licheniformis, B. subtilis, B. thermoamylovorans,and B. hisashii), B (B. subtilis, B. thermoamylovorans, B. thermoruber, and B. hisashii), and C (B. subtilis, B. thermoamylovorans, and B. hisashii), and the composting lasted 7–14 days. Lignin and cellulose degradation rates in B during composting were 17.1% and 36.7% at the cooling stage, respectively. Redundancy analysis showed that degradation of lignocellulose in the thermophilic stage was mainly related to the secretion of lignocellulose-degrading enzymes after microbial inoculation. 16S rRNA sequencing revealed that Bacillus (20.3%) and Thermobifida (20.2%) were the dominant genera. Inoculation with a combination including B. thermoruber was a feasible way to increase lignocellulose degradation and promote maturity in sewage sludge composting.

Effect of microbial inoculant on the fermentation profile, nutritional value and microbial population on corn, sorghum, and pearl millet silages

The objective of the present study was to evaluate the use of microbial inoculant on the chemical composition, in vitro gas production, pH, dry matter losses, aerobic stability and microbial population on silages of corn, sorghum and pearl millet in plastic bags silos (without vacuum). The experiment was carried out in a randomized block design, in a 2 × 3 factorial scheme, with and without (control) inoculant consisting of Lactobacillus plantarum and Propionibacterium acidipropionici and on three crops, corn, sorghum and pearl millet, with four replicates. The use of the inoculant did not affect the chemical composition of the silages, except the crude protein (P = 0.0062) and lignin (P = 0.0567) contents. Gas production was neither affected (P &gt; 0.05) by the inoculant nor by the crop. Regarding aerobic stability, we observed that the inoculant affected the temperature of the sorghum silage (P = 0.0123). The inoculant decreased the N-NH3 (P =0.0095) content and increased (P = 0.0441) the lactic acid bacteria population in the silages. Thus, the microbial inoculant did not improve the fermentation profile or nutritional value of corn, pearl millet and sorghum silages in plastic bag silos (without vacuum).

Effect of Microbial Inoculant on Physicochemical and Microbiological Properties of Cassava Fermentation Process and Fufu Produced

Aim: The effects of adding a microbiological inoculant on the physicochemical and microbiological properties during the fermentation process of cassava (Manihot esculenta Crantz) and on the sensory characteristics of the fufu produced using a local Bambili cassava variety were examined.&#x0D; Study Design: Completely Randomized Design was applied for this study.&#x0D; Place and Duration of Study: Study was carried out at the Food Technology and Post-Harvest Programme Laboratory (FTPHL) of the Institute of Agricultural Research for Development (IRAD) Bambui, North West Region of Cameroon, between January and April 2020.&#x0D; Methodology: Cassava was soaked in water and three treatments: 0%, 1% and 4% Light Matrix Organics (LMO) added to the water. The fixed submerged fermentation was used. Water samples were randomly collected daily and analysed for pH, temperature, Titratable Acidity (TA) and microbial counts. The experiment was carried out in triplicates, varying temperature each time (35oC in trial 1, 32oC in trial 2 and 21oC in trial 3). Sensory evaluation was carried out on the fufu produced.&#x0D; Results: Temperature, pH, TA and microbial counts followed the same trend in all 3 treatments. TA increased from 0.01-0.15%, while pH decreased from 6.9-4.85. Temperature increased then dropped at the end of the experiment. Total bacterial counts increased from log10 (3.49) to log10 (6.9) CFUml-1. Yeasts and moulds increased from log10 (7.15) CFUml-1 and then dropped to log10 (5.48) CFUml-1 at the end of the experiment. Coliforms decreased from log10 (4.66) CFUml-1 to log10 (3.30) CFUml-1. The above parameters did not vary significantly (p&lt;0.05) within treatments. Also, soaking temperature affected the duration of fermentation, hence the finished product. The natural fermentation process was preferred for colour, taste and flavour while the 1% LMO sample was preferred for texture.&#x0D; Conclusion: Under good hygienic conditions; water fufu produced by natural fermentation will be of good quality for consumption.

The effects of microbial inoculation and intercropping on yield and active ingredients of savory (Satureja hortensis L.) intercropped with common bean (Phaseolus vulgaris L.)

The effects of microbial inoculation and intercropping on yield and active ingredients of savory (Satureja hortensis L.) intercropped with common bean (Phaseolus vulgaris L.)

Microbial inoculants and struvite improved organic matter humification and stabilized phosphorus during swine manure composting: Multivariate and multiscale investigations

The combined effects of microbial inoculants (MI) and magnesium ammonium phosphate (MAP; struvite) on organic matter (OM) biodegradation and nutrients stabilization during biowaste composting have not yet been investigated. Therefore, the effects of MI and MAP on OM stability and P species during swine manure composting were investigated using geochemical and spectroscopic techniques. MI promoted the degradation of carbohydrates and aliphatic compounds, which improved the degree of OM mineralization and humification. MI and MAP promoted the redistribution of P fractions and species during composting. After composting, the portion of water-soluble P decreased from 50.0% to 23.0%, while the portion of HCl-P increased from 18.5% to 33.5%, which mean that MI and MAP can stabilize P and mitigate its potential loss during composting. These findings indicate that MI can be recommended for enhancing OM biodegradation and stabilization of P during biowastes composting, as a novel trial for the biological waste treatment.

Effects of PGPR, AMF and Trichoderma Applications on Adaptation Abilities to Different Biotic and Abiotic Conditions in Medicinal and Aromatic Plants

Medicinal and aromatic plants are valuable sources of herbal products worldwide due to their secondary metabolite content, high antioxidant activities and many other biological activities. As a result of the developing technology, the demand for natural active substances obtained from plants has increased. For use, plants collected from nature do not have the desired quality standards. For this reason, sustainability can be achieved by using microbial inoculants as well as many biotechnological and molecular approaches such as micro propagation, synthetic seed technology to increase the yield and quality standards of medicinal and aromatic plants. Thanks to microbial inoculants, yield increase can be realized and at the same time, product quality can be contributed due to increased soil quality. In this review, it was aimed to evaluate the important roles of plant growth promoting rhizobacteria (PGPR), Arbiscular mycorrhizal fungi and Trichoderma inoculants in increasing productivity, nutrient uptake and resistance of medicinal and aromatic plants to environmental stresses in the light of literature. In this review, the variation in the resistance of plants to environmental stresses is summarized by evaluating the ultimate effects of microbial inoculants alone and in combination. In addition, it has been added to the evaluation in studies to prevent the decrease of secondary metabolite content formed under environmental stress conditions in medicinal and aromatic plants by microorganisms.

Effects of microbial inoculation on dry matter losses, fermentation profile, and aerobic stability of wet brewers grain stored with increasing concentrations of dry ground corn

The objective of this study was to evaluate the effects of microbial inoculation and storage length on the fermentation profile, dry matter losses and aerobic stability of wet brewers grains (WBG) ensiled with increasing amounts of dry ground corn (DGC). Pure WBG (210 g/kg of dry matter [DM]) and 3 mixtures of WBG and DGC were prepared targeting for a dry matter content of 350 g/kg (RC35), 500 g/kg (RC50) or 650 g/kg (RC65). Distilled water (CON) or one of two microbial inoculants were applied, a combination with Pediococcus pentosaceus at 1 × 105 cfu/g of fresh forage and Propionibacterium freudenreichii at 2 × 104 cfu/g of fresh forage (PPPF), or a heterofermentative with Lactobacillus buchneri at 7.5 × 105 cfu/g of fresh forage and Pediococcus pentosaceus at 1 × 105 cfu/g of fresh forage (LBPP). Mixtures were ensiled in laboratory silos in quadruplicate and opened at two storage lengths (SL), 30 or 60 days (30 d and 60 d, respectively). Data were analyzed as a completely randomized design with a 4 × 3 × 2 factorial arrangement of treatments using Proc Glimmix of SAS. Butyric acid concentration decreased (P < 0.04) with addition DGC regardless of microbial inoculation. Mixtures with greater amounts of DGC (RC50 and RC60) reduced (P < 0.01) DM losses and pH, regardless of inoculation or storage length. Lactic acid concentration was greater (P ≤ 0.05) with intermediate addition of corn (RC35 and RC50). Acetic acid concentration did not differ among inoculation treatments when corn was added to the mixtures; however, LBPP increased 1,2-propanediol in RC50 and RC60. Moreover, LBPP increased aerobic stability only for the RC65 mixture. In conclusion, the addition of DGC to WBG improves fermentation and decreases DM losses, while inoculation with LBPP can improve aerobic stability in RC65. Our data suggests that adding DGC to WBG is a feasible strategy to store WBG for up to 60 days and inoculation with PPPF and LBPP can improve further the conditions of the WBG and DGC mixtures silage.

The Integrated Effect of Microbial Inoculants and Biochar Types on Soil Biological Properties, and Plant Growth of Lettuce (Lactuca sativa L.).

Numerous reports confirm the positive effect of biochar application on soil properties and plant development. However, the interaction between root-associated beneficial microbes and different types of biochar is not well understood. The objective of this study was to evaluate the plant growth of lettuce after the application of three types of biochar in loamy, sandy soil individually and in combination with plant-beneficial microbes. Furthermore, total microbial activity in rhizosphere soil of lettuce was measured by means of fluorescein diacetate (FDA) hydrolase and enzyme activities linked to carbon, nitrogen, and phosphorus cycling. We used three types of biochar: (i) pyrolysis char from cherry wood (CWBC), (ii) pyrolysis char from wood (WBC), and (iii) pyrolysis char from maize (MBC) at 2% concentration. Our results showed that pyrolysis biochars positively affected plant interaction with microbial inoculants. Plant dry biomass grown on soil amended with MBC in combination with Klebsiella sp. BS13 and Klebsiella sp. BS13 + Talaromyces purpureogenus BS16aPP inoculants was significantly increased by 5.8% and 18%, respectively, compared to the control plants. Comprehensively, interaction analysis showed that the biochar effect on soil enzyme activities involved in N and P cycling depends on the type of microbial inoculant. Microbial strains exhibited plant growth-promoting traits, including the production of indole 3-acetic-acid and hydrogen cyanide and phosphate-solubilizing ability. The effect of microbial inoculant also depends on the biochar type. In summary, these findings provide new insights into the understanding of the interactions between biochar and microbial inoculants, which may affect lettuce growth and development.

Impact of native spray‐dried lactic acid bacteria, packing density and wilting time on fermentation characteristics of experimental maize and lucerne silages

AbstractThis study aimed at investigating the effects of an autochthonous microbial inoculant microencapsulated by spray‐drying on fermentation parameters, microbiological composition, mycotoxin level and aerobic stability of maize and lucerne silages. Experiment 1, a completely randomized design with a 2 × 2 × 4 factorial arrangement of treatments, evaluated inoculation (control or Lactobacillus plantarum Hv75, Pediococcus acidilactici 3903 and Lactobacillus buchneri B463), packing density (148.5 kg dry matter (DM)/m3 or 181.5 kg DM/m3) and storage period (0, 1, 30 or 60 days) in maize silage. Lactic acid bacteria (LAB) supplementation produced higher DM and lower acetic acid and deoxynivalenol contents compared to the control (p &lt; 0.05). However, these differences were small in terms of practical applications. Experiment 2 evaluated effects of microbial inoculation (similar as in experiment 1), wilting time (3 or 21 h) and storage period (0, 3, 30 or 60 days) in lucerne silage. LAB supplementation increased DM and lactic acid content, reduced pH and concentrations of acetic acid, ethanol and ammonia nitrogen/total nitrogen compared to the control (p &lt; 0.05). In addition, inoculation increased total LAB population and decreased yeast and mould counts (p &lt; 0.05). Although the strains displayed potential to be used as a bio‐inoculant at different lucerne moisture levels, prolonged wilting positively influenced DM, crude protein and fibre degradation (p &lt; 0.05). Therefore, the addition of this spray‐dried inoculant to lucerne silages with longer wilting could be recommended for the attainment of silage quality.

Effect of Microbial Inoculant “Yume-bio” on Growth and Yield of Field Crops

Effect of Microbial Inoculant “Yume-bio” on Growth and Yield of Field Crops

The effect of microbial inoculants and molasses on quality and in vitro digestibility of silages prepared with different proportions of ryegrass and Hungarian vetch

In this study, it was aimed to determine the effect of microbial inoculants and molasses on the quality and in vitro digestibility of the silages ensiled from the cultivation of different proportions of ryegrass-Hungarian vetch mixtures grown in Central Anatolian conditions. For this purpose, 5% molasses and 10 g/ton (1.25 × 10$^{11}$ CFU/g) inoculant were added to silages of ryegrass (Lolium multiflorum L.) containing 20%, 40%, 60%, and 80% Hungarian vetch (Vicia pannonica L.), under laboratory conditions. The prepared silages were opened at the end of 60 days and their physical analysis, chemical contents, fermentation parameters, in vitro digestibilities using rumen inocula obtained from cannulated Holstein cow, and energy levels were determined. In the study, it was determined that the microbial inoculant increased the lactic acid level significantly (p < 0.05). In vitro digestibility of organic matter and energy values increased in silages containing 60% HV compared to other silages and with both additives (p < 0.05). The neutral detergent fiber levels increased in mixtures containing 40% and 60% Hungarian vetch (p < 0.05). The increase in the vetch ratio affected the external appearance of the silages negatively (p < 0.05), and the physical properties were adversely affected by the inoculant (p < 0.05). As a result, it was determined that Hungarian vetch can be mixed with ryegrass up to 80% with and without inoculant and molasses additive to obtain high-quality silage. But the highest digestibility values were obtained when Hungarian vetch was mixed at a 60% level. It would be more appropriate to prefer molasses to avoid undesired changes in physical properties.

Microbial inoculation and fertilizer application on growth of cowpea and spore-based assemblages of arbuscular mycorrhizal fungi in its rhizophere.

In this study, the effect of microbial inoculants and fertilizer application on cowpea (BRS Pujante) growth and on the structure and composition of arbuscular mycorrhizal fungi (AMF) assemblages were evaluated. A completely randomized experiment was set up involving 17 treatments: four with AMF, three with nodulating bacteria, six with AMF + nodulating bacteria, two with phosphorus, one with nitrogen and one control (reference) in five replicates. Plant growth and nutritional content, mycorrhizal colonization, glomerospores number, spore-based AMF assemblages and ecological indices were evaluated. Mycorrhizal inoculants associated with Bradyrhizobium BR3267 strain were more effective than the Microvirga BR3296 strain. Multidimensional scaling analysis showed that Acaulospora longula treatments were more similar among themselves, and distinct from the other treatments. A difference was observed in the structure of AMF community assemblage between treatments with G. albida + Bradyrhizobium BR 3267 and A. longula, with greater Shannon diversity and Pielou equitability indices in the first treatment and greater dominance in the treatment with A. longula only. Long-term studies are required to determine if the successful establishment of A. longula among indigenous species persists over time and if its dominant behavior is not deleterious to the AMF native community.

Effects of microbial inoculants on soil carbon stock, enzymatic activity, and above ground and belowground biomass in marginal lands of Northern India

AbstractRestoration practices in marginal lands for food production are the most important sustainability challenge for humans at the global level. Nature‐based solutions (NBS) are among the best interventions to improve soil health, which directly enhances the soil productivity and biodiversity for improved sustainability of ecosystems. Our field experiment was conducted to evaluate the effects of three inoculants, two of which were bacterial: Azotobacter chroococcum (T1), Acetobacter diazotrophicus (T2), and the third fungal: Aspergillus awamori (T3) on soil properties, plant biomass, enzymatic activities (phosphatase, dehydrogenase activity), and soil carbon stock in marginal lands. The experimental results clearly revealed that the inoculations significantly enhanced plant growth and biomass (p &lt; 0.01). The soil enzyme (dehydrogenase and phosphatase) activities increased under T3 and T2 treatments in response to inoculation. Interestingly, the significant results were observed in T3 and T1 treatment in the 4th year of observation for soil carbon stock (53.06 Mg ha−1 yr−1 and 51.41 Mg ha−1 yr−1, respectively). The total soil carbon stock was found to be 38.60 Mg ha−1 yr−1 in control plots. The inoculation enhanced (p ≤ 0.05) the soil biological properties like microbial biomass carbon as 267.62 ± 18.73 μgg−1 to 894.24 ± 41.65 μg g−1. We conclude that selected inoculations in marginal lands can provide a suitable option for eco‐restoration and can sequester more atmospheric CO2 in to stable carbon pools to achieve UN Sustainable Development Goals and food security.

The Effect of Microbial Inoculation under Various Nitrogen Regimes on the Uptake of Nutrients by Apple Trees

The European Green Deal strategy currently implemented in the EU aims to, among others, reduce the negative impact of fertilization on the environment. One of the solutions influencing the nutritional status of plants and the improvement of soil quality is the use of plant symbiosis with microorganisms. Thus, in this study we investigated the effect of arbuscular mycorrhizal fungi (AMFs) and plant-growth-promoting rhizobacteria (PGPR) colonization on the nutritional status of apple leaves and fruit, depending on the nitrogen treatment. In a fully factorial experiment, trees were grown for nine years with or without AMFs and PGPR. We compared several ammonium nitrate treatments as well as growth without fertilization as a control. The interactions between inoculation and doses of nitrogen fertilization were observed. AMF + PGPR significantly increased the concentration of nitrogen (N), phosphorus (P), and potassium (K) in leaves up to 5%, 23%, and 19%, respectively, depending on the N dosage. Conversely, in uninoculated trees, the nitrogen treatment had a negative impact on the leaf P mineral status. On the other hand, under microbial inoculation conditions, the dose of 100 kg N∙ha−1 diminished the leaf phosphorus content in comparison to other N doses, by a maximum of 9.6%. AMF + PGPR, depending on the N treatment, either did not influence or it decreased the Mg and Ca concentrations in the leaves by maximums of 8% and 15%, respectively. Microbial inoculation had no effect on the acquisition of Ca and Mg by fruits, except for the coupled negative influence of the 100 kg N∙ha−1 treatment. Symbiosis positively conditioned the K in fruits under a specific N regime—100 kg N∙ha−1 divided into two applications during the season and 50 kg N∙ha−1 applied to the herbicide strip, increasing the concentration by approximately 4% and 8%, respectively. This study greatly contributes to our understanding of the benefits of AMF and PGPR on perennials and encourages the future exploration of their effects on apple yield and fruit quality.

An initial study of woody-debris decomposition to reduce risk of repeated-fire incidence in tropical peatland ecosystem

As peatland ecosystems were formed from layered partially decomposed plant biomass, they were considered more vulnerable to fire, especially during extreme drought season. Woody debris accumulation in the field may increase the risk of peatland fire. In order to minimize the chance of repeated fire, an initial study on woody debris decomposition by employing a consortium of wood-decay microbes (consists of Scedosporium apiospermum, Pycnoporus sp., Pycnoporus sanguineus, and unidentified cellulolytic bacterial isolate) was conducted. Series of experiments of in vitro-, semi-controlled-, and field- conditions were carried out. After 12-weeks of incubation, the in vitro trial showed that all treatments on mineral-soil basal media were colonized by fungal mycelia, including the control. Meanwhile, the treatments on peat soil seem less supportive for fungal growth since only six out of ten treatments have been colonized by fungal mycelia. In semi-controlled conditions, effects of microbial inoculation showed questionable results as the trials were randomly occupied by Schizophylum commune, which was not included in the microbial inoculants. Un-clear effects of the microbial inoculants were also observed on the field trial as no significant difference of dry-weight loss between the inoculated woody logs and the un-inoculated control. Further comprehensive studies to reduce woody debris in peatland areas are required.

Malus Antioxidant Metabolism Following Bacterial–Fungal Inoculation in Organic Farming: From Root to Fruit

This study investigated the antioxidant status of roots, leaves, and fruit upon microbial inoculation (AMF+PGPR, arbuscular mycorrhizal fungi, and plant growth-promoting rhizobacteria, respectively) of young organically farmed apple trees over two growing seasons. Three cultivars—‘Topaz’, ‘Chopin’, and ‘Odra’—were selected to test the relationship between inoculation and enzymatic and non-enzymatic antioxidant components. The antioxidant metabolism was highly dependent on tissue type and growing season. The greatest effect on antioxidant status following application of the inoculum was found in roots, then leaves, but it was almost negligible in fruit. Roots were influenced most by application of the inoculum in the first growing season, while leaves were influenced most in the second season. Considerable differences between the inoculated and control plants were found for root glutathione reductase (GR) and catalase (CAT) activity, as well as glutathione and ascorbate contents; root phenolics were not influenced by inoculation. In the case of leaves, effect of microbial inoculation on GR activity was revealed in the first growing season, while for global phenolics in the second season, and only the concentration of glutathione was significantly higher in the leaves of inoculated trees in both growing seasons. Leaf ascorbate content and CAT activity were not influenced by the microbial inoculation. The control and inoculated trees expressed a similar total antioxidant capacity, irrespective of the tissue type tested. Furthermore, the response of the cultivars to inoculation varied and also changed in consecutive growing seasons. Based on this study, it is likely that the effect of microbial inoculum as a tool for enhancing health-promoting properties in the fruit of perennial plants is weaker than that described for vegetables where different plant organs are edible.