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Bioaugmentation constitutes a viable approach for the bioremediation of soils polluted by organic chemicals, but limitations may arise due to the poor in situ performance of the inoculated microorganisms. This chapter examines these – poorly understood – drawbacks in the light of the latest advances in microbial ecology and bioremediation strategies. We discuss how biotic and abiotic factors may compromise the establishment and activity of microbial inoculants in soil, as well as how to design efficient inoculants that exhibit increased robustness and dispersal. Innovative approaches could include taking advantage of microbial networks through bacterial consortia with complementary catabolic capabilities, and fungal- and plant-bacterial associations that provide an enhanced bacterial dispersion in water-unsaturated soil conditions. We also provide recommendations on the most convenient strategies for inoculant production and application, considering their mass production, the optimal dosing ratios and the optimised use of platforms for microbial action in soil, such as solid carriers (e.g. biochar) and plants.

Background: No studies have been conducted evaluating sugarcane silage associated with both Lactobacillus plantarum and Pediococcus pentosaceus for lactating dairy cows. Objective: To evaluate diets containing different roughages with and without microbial inoculants on intake, digestibility and milk yield of medium-producing cows. Methods: A total of 15 Holstein cows distributed into a randomized block design were used. Dietary treatments were: 1) a corn silage-based diet (CS), 2) a fresh sugarcane-based diet (SC), 3) a sugarcane silage ensiled without inoculant (SS), 4) sugarcane silage ensiled with Lactobacillus buchneri (SSLB), and 5) sugarcane silage ensiled with Lactobacillus plantarum and Pediococcus pentosaceus (SSLP). Results: Digestible organic matter intake (DOMI) was lower (p<0.05) in cows fed SSLB (9.77 kg day-1) when compared with cows fed CS (13.29 kg day-1) and SSLP (12.42 kg day-1). Ensiling of sugarcane increased intake of neutral detergent fiber (NDF) compared to SC (mean of 6.00 kg day-1 versus 4.97 kg day-1; p<0.05). Dry matter digestibility was greater (p<0.05) in CS (77.80%) compared with diets based on sugarcane silage, whereas NDF digestibility was lower for treatments with sugarcane (p<0.05). Milk yield was similar among CS (27.99 kg), SC (25.59 kg), and silages with additives (25.47 and 27.07 for SSLB and SSLP, respectively). Cows fed CS produced more fat-corrected milk (25.89 kg) than those fed sugarcane-based diets (p<0.05). Conclusions: Fresh sugarcane or sugarcane silage with additives can be used as a roughage source for dairy cows producing up to 23.43 kg d-1 fat-corrected milk, considering the total diet is properly balanced., Antecedentes: Há carência de estudos avaliando a adição de Lactobacillus plantarum e Pediococcus pentosaceus na silagem de cana-de-açúcar para vacas em lactação. Objetivo: Avaliar dietas contendo diferentes forragens e silagens com e sem inoculantes microbianos sobre o consumo, digestibilidade e produção de leite de vacas de média produção de leite. Métodos: Quinze vacas Holandesas foram distribuídas em um delineamento em blocos casualizados. Os tratamentos foram: 1) dieta com silagem de milho (CS), 2) dieta com cana-de-açúcar fresca (SC), 3) dieta com silagem de cana ensilada sem inoculantes (SS), 4) dieta com silagem de cana-de-açúcar ensilada com Lactobacillus buchneri (SSLB), ou 5) dieta com silagem de canade-açúcar ensilada com Lactobacillus plantarum, and Pediococcus pentosaceus (SSLP). Resultados: O consumo de matéria orgânica digestível foi menor (p<0,05) na dieta SSLB (9,77 kg day-1) comparada com CS (13,29 kg dia-1) e SSLP (12,42 kg dia-1). A ensilagem da cana-de-açúcar promoveu maior consumo de fibra em detergente neutro (FDN) em comparação com SC (média de 6,00 kg dia-1 versus 4.97 kg dia-1; p<0.05). A digestibilidade da matéria seca foi maior (p<0,05) para a dieta CS (77,80%) comparada com as dietas com silagem de cana-de-açúcar, enquanto que a digestibilidade da FDN foi menor para as dietas baseadas em cana-de-açúcar (p<0,05). A produção de leite foi similar entre CS (27,99 kg), SC (25,59 kg) e silagens com aditivos (25,47 e 27,07 para SSLB e SSLP, respectivamente). Vacas alimentadas com silagem de milho produziram mais leite corrigido para gordura (25,89 kg) que aquelas alimentadas com dietas baseadas em cana-de-açúcar (p<0,05). Conclusão: A cana-de-açúcar fresca ou ensilada com aditivos pode ser utilizada como fonte volumosa para vacas produzindo até 23,43 kg d-1 leite corrigido para gordura, desde que a dieta total esteja apropriadamente balanceada., Antecedentes: No existen estudios que evalúen la adición de Lactobacillus plantarum y Pediococcus pentosaceus en el ensilaje de caña de azúcar para vacas lactantes. Objetivo: Evaluar dietas con diferentes forrajes y ensilajes con y sin inoculantes microbianos sobre el consumo, digestibilidad y producción láctea de vacas de mediana producción. Metodología: Quince vacas Holstein se distribuyeron en un diseño de bloques al azar. Los tratamientos fueron: 1) dieta con ensilaje de maíz (CS), 2) dieta con caña de azúcar fresca (SC), 3) dieta con ensilaje de caña sin inoculantes (SS), 4) dieta con ensilaje de caña de azúcar ensilada con Lactobacillus buchneri (SSLB), y 5) dieta con ensilaje de caña de azúcar ensilada con Lactobacillus plantarum y Pediococcus pentosaceus (SSLP). Resultados: El consumo de materia orgánica digestible fue menor (p<0,05) en la dieta SSLB (9,77 kg day-1) en comparación con CS (13,29 kg dia-1) y SSLP (12,42 kg dia-1). El ensilaje de caña de azúcar promovió un mayor consumo de fibra detergente neutra (NDF) en comparación con SC (promedio de 6,00 kg dia-1 versus 4,97 kg dia-1; p<0,05). La digestibilidad de la materia seca fue mayor (p<0,05) para la dieta CS (77,80%) en comparación con las dietas con ensilaje de caña de azúcar, mientras que la digestibilidad de la NDF fue menor para las dietas a base de caña de azúcar (p<0,05). La producción de leche fue similar entre CS (27,99 kg), SC (25,59 kg) y ensilajes con aditivos (25,47 y 27,07 para SSLB y SSLP, respectivamente). Las vacas alimentadas con ensilaje de maíz produjeron más leche corregida por grasa (25,89 kg) que las alimentadas con dietas a base de caña de azúcar (p<0,05). Conclusión: La caña de azúcar fresca o ensilada con aditivos se puede utilizar como fuente de forraje para vacas que producen hasta 23,43 kg d-1 leche corregida por grasa, siempre que la dieta total esté equilibrada adecuadamente.

Background: No studies have been conducted evaluating sugarcane silage associated with both Lactobacillus plantarum and Pediococcus pentosaceus for lactating dairy cows. Objective: To evaluate diets containing different roughages with and without microbial inoculants on intake, digestibility and milk yield of medium-producing cows. Methods: A total of 15 Holstein cows distributed into a randomized block design were used. Dietary treatments were: 1) a corn silage-based diet (CS), 2) a fresh sugarcane-based diet (SC), 3) a sugarcane silage ensiled without inoculant (SS), 4) sugarcane silage ensiled with Lactobacillus buchneri (SSLB), and 5) sugarcane silage ensiled with Lactobacillus plantarum and Pediococcus pentosaceus (SSLP). Results: Digestible organic matter intake (DOMI) was lower (p<0.05) in cows fed SSLB (9.77 kg day-1) when compared with cows fed CS (13.29 kg day-1) and SSLP (12.42 kg day-1). Ensiling of sugarcane increased intake of neutral detergent fiber (NDF) compared to SC (mean of 6.00 kg day-1 versus 4.97 kg day-1; p<0.05). Dry matter digestibility was greater (p<0.05) in CS (77.80%) compared with diets based on sugarcane silage, whereas NDF digestibility was lower for treatments with sugarcane (p<0.05). Milk yield was similar among CS (27.99 kg), SC (25.59 kg), and silages with additives (25.47 and 27.07 for SSLB and SSLP, respectively). Cows fed CS produced more fat-corrected milk (25.89 kg) than those fed sugarcane-based diets (p<0.05). Conclusions: Fresh sugarcane or sugarcane silage with additives can be used as a roughage source for dairy cows producing up to 23.43 kg d-1 fat-corrected milk, considering the total diet is properly balanced., Antecedentes: Há carência de estudos avaliando a adição de Lactobacillus plantarum e Pediococcus pentosaceus na silagem de cana-de-açúcar para vacas em lactação. Objetivo: Avaliar dietas contendo diferentes forragens e silagens com e sem inoculantes microbianos sobre o consumo, digestibilidade e produção de leite de vacas de média produção de leite. Métodos: Quinze vacas Holandesas foram distribuídas em um delineamento em blocos casualizados. Os tratamentos foram: 1) dieta com silagem de milho (CS), 2) dieta com cana-de-açúcar fresca (SC), 3) dieta com silagem de cana ensilada sem inoculantes (SS), 4) dieta com silagem de cana-de-açúcar ensilada com Lactobacillus buchneri (SSLB), ou 5) dieta com silagem de canade-açúcar ensilada com Lactobacillus plantarum, and Pediococcus pentosaceus (SSLP). Resultados: O consumo de matéria orgânica digestível foi menor (p<0,05) na dieta SSLB (9,77 kg day-1) comparada com CS (13,29 kg dia-1) e SSLP (12,42 kg dia-1). A ensilagem da cana-de-açúcar promoveu maior consumo de fibra em detergente neutro (FDN) em comparação com SC (média de 6,00 kg dia-1 versus 4.97 kg dia-1; p<0.05). A digestibilidade da matéria seca foi maior (p<0,05) para a dieta CS (77,80%) comparada com as dietas com silagem de cana-de-açúcar, enquanto que a digestibilidade da FDN foi menor para as dietas baseadas em cana-de-açúcar (p<0,05). A produção de leite foi similar entre CS (27,99 kg), SC (25,59 kg) e silagens com aditivos (25,47 e 27,07 para SSLB e SSLP, respectivamente). Vacas alimentadas com silagem de milho produziram mais leite corrigido para gordura (25,89 kg) que aquelas alimentadas com dietas baseadas em cana-de-açúcar (p<0,05). Conclusão: A cana-de-açúcar fresca ou ensilada com aditivos pode ser utilizada como fonte volumosa para vacas produzindo até 23,43 kg d-1 leite corrigido para gordura, desde que a dieta total esteja apropriadamente balanceada., Antecedentes: No existen estudios que evalúen la adición de Lactobacillus plantarum y Pediococcus pentosaceus en el ensilaje de caña de azúcar para vacas lactantes. Objetivo: Evaluar dietas con diferentes forrajes y ensilajes con y sin inoculantes microbianos sobre el consumo, digestibilidad y producción láctea de vacas de mediana producción. Metodología: Quince vacas Holstein se distribuyeron en un diseño de bloques al azar. Los tratamientos fueron: 1) dieta con ensilaje de maíz (CS), 2) dieta con caña de azúcar fresca (SC), 3) dieta con ensilaje de caña sin inoculantes (SS), 4) dieta con ensilaje de caña de azúcar ensilada con Lactobacillus buchneri (SSLB), y 5) dieta con ensilaje de caña de azúcar ensilada con Lactobacillus plantarum y Pediococcus pentosaceus (SSLP). Resultados: El consumo de materia orgánica digestible fue menor (p<0,05) en la dieta SSLB (9,77 kg day-1) en comparación con CS (13,29 kg dia-1) y SSLP (12,42 kg dia-1). El ensilaje de caña de azúcar promovió un mayor consumo de fibra detergente neutra (NDF) en comparación con SC (promedio de 6,00 kg dia-1 versus 4,97 kg dia-1; p<0,05). La digestibilidad de la materia seca fue mayor (p<0,05) para la dieta CS (77,80%) en comparación con las dietas con ensilaje de caña de azúcar, mientras que la digestibilidad de la NDF fue menor para las dietas a base de caña de azúcar (p<0,05). La producción de leche fue similar entre CS (27,99 kg), SC (25,59 kg) y ensilajes con aditivos (25,47 y 27,07 para SSLB y SSLP, respectivamente). Las vacas alimentadas con ensilaje de maíz produjeron más leche corregida por grasa (25,89 kg) que las alimentadas con dietas a base de caña de azúcar (p<0,05). Conclusión: La caña de azúcar fresca o ensilada con aditivos se puede utilizar como fuente de forraje para vacas que producen hasta 23,43 kg d-1 leche corregida por grasa, siempre que la dieta total esté equilibrada adecuadamente.

Includes bibliographical references (pages 117-132)., Includes abstract and appendices.

Plant protection with beneficial microbes is considered to be a promising alternative to chemical control of pests and pathogens. Beneficial microbes can boost plant defences via induced systemic resistance (ISR), enhancing plant resistance against future biotic stresses. Although the use of ISR-inducing microbes in agriculture seems promising, the activation of ISR is context-dependent: it often occurs only under particular biotic and abiotic conditions, thus making its use unpredictable and hindering its application. Although major breakthroughs in research on mechanistic aspects of ISR have been reported, ISR research is mainly conducted under highly controlled conditions, differing from those in agricultural systems. This forms one of the bottlenecks for the development of applications based on ISR-inducing microbes in commercial agriculture. We propose an approach that explicitly incorporates context-dependent factors in ISR research to improve the predictability of ISR induction under environmentally variable conditions. Here, we highlight how abiotic and biotic factors influence plant–microbe interactions in the context of ISR. We also discuss the need to raise awareness in harnessing interdisciplinary efforts between researchers and stakeholders partaking in the development of applications involving ISR-inducing microbes for sustainable agriculture.

The diversity of salt-tolerant cultivable endophytic bacteria associated with the halophyte New Zealand spinach (Tetragonia tetragonioides (Pall.) Kuntze) was studied, and their plant beneficial properties were evaluated. The bacteria isolated from leaves and roots belonged to Agrobacterium, Stenotrophomonas, Bacillus, Brevibacterium, Pseudomonas, Streptomyces, Pseudarthrobacter, Raoultella, Curtobacterium, and Pantoea. Isolates exhibited plant growth-promoting traits, including the production of a phytohormone (indole 3-acetic-acid), cell wall degrading enzymes, and hydrogen cyanide production. Furthermore, antifungal activity against the plant pathogenic fungi Fusarium solani, F. oxysporum, and Verticillium dahliae was detected. Ten out of twenty bacterial isolates were able to synthesize ACC deaminase, which plays a vital role in decreasing ethylene levels in plants. Regardless of the origin of isolated bacteria, root or leaf tissue, they stimulated plant root and shoot growth under 200 mM NaCl conditions. Our study suggests that halophytes such as New Zealand spinach are a promising source for isolating halotolerant plant-beneficial bacteria, which can be considered as potentially efficient biofertilizers in the bioremediation of salt-affected soils., Peer Reviewed

The diversity of salt-tolerant cultivable endophytic bacteria associated with the halophyte New Zealand spinach (Tetragonia tetragonioides (Pall.) Kuntze) was studied, and their plant beneficial properties were evaluated. The bacteria isolated from leaves and roots belonged to Agrobacterium, Stenotrophomonas, Bacillus, Brevibacterium, Pseudomonas, Streptomyces, Pseudarthrobacter, Raoultella, Curtobacterium, and Pantoea. Isolates exhibited plant growth-promoting traits, including the production of a phytohormone (indole 3-acetic-acid), cell wall degrading enzymes, and hydrogen cyanide production. Furthermore, antifungal activity against the plant pathogenic fungi Fusarium solani, F. oxysporum, and Verticillium dahliae was detected. Ten out of twenty bacterial isolates were able to synthesize ACC deaminase, which plays a vital role in decreasing ethylene levels in plants. Regardless of the origin of isolated bacteria, root or leaf tissue, they stimulated plant root and shoot growth under 200 mM NaCl conditions. Our study suggests that halophytes such as New Zealand spinach are a promising source for isolating halotolerant plant-beneficial bacteria, which can be considered as potentially efficient biofertilizers in the bioremediation of salt-affected soils., Peer Reviewed

Aims The hydrolysis of organic P in soils is a relevant aspect contributing to the supply P to plants, which is affected by adsorbent capacity and biological properties of soils. This work aimed at studying the contribution of phytate to plant nutrition as affected by Fe oxides and phosphohydrolases releasing microorganisms in the growing medium. Methods An experiment with cucumber and myo-inositol hexakiphosphate (myo-Ins6P) as P source was performed involving two factors: Fe oxide –ferrihydrite– rates (0, 100, 300 mg kg−1 of citrate–ascorbate extractable Fe), and microbial inoculation (Trichoderma asperellum T34, Bacillus subtilis QST713, and noninoculated). Results P uptake decreased with increased Fe oxides in the growing media. Phytase activity and organic anions concentration increased with increased Fe oxides in the media. Most of the P supplied was recovered as inorganic P at the highest Fe oxide concentration. Inoculants did not improve P uptake by plants, despite B. subtilis promoted an enhanced hydrolytic activity at the highest Fe oxide concentration. Conclusions An increased adsorption capacity of the growing media restricts the use of myo-Ins6P as P source by plants. This was not the result of its stabilization through adsorption or a decreased hydrolytic activity, but of the adsorption of inorganic P on Fe oxides after hydrolysis.

Plant protection with beneficial microbes is considered to be a promising alternative to chemical control of pests and pathogens. Beneficial microbes can boost plant defences via induced systemic resistance (ISR), enhancing plant resistance against future biotic stresses. Although the use of ISR-inducing microbes in agriculture seems promising, the activation of ISR is context-dependent: it often occurs only under particular biotic and abiotic conditions, thus making its use unpredictable and hindering its application. Although major breakthroughs in research on mechanistic aspects of ISR have been reported, ISR research is mainly conducted under highly controlled conditions, differing from those in agricultural systems. This forms one of the bottlenecks for the development of applications based on ISR-inducing microbes in commercial agriculture. We propose an approach that explicitly incorporates context-dependent factors in ISR research to improve the predictability of ISR induction under environmentally variable conditions. Here, we highlight how abiotic and biotic factors influence plant–microbe interactions in the context of ISR. We also discuss the need to raise awareness in harnessing interdisciplinary efforts between researchers and stakeholders partaking in the development of applications involving ISR-inducing microbes for sustainable agriculture.

Includes bibliographical references (pages 117-132)., Includes abstract and appendices.

Increasing the length of storage of whole-plant corn silage (WPCS) has been shown to increase ruminal in vitro starch digestibility by facilitating hydrolysis of the protein matrix surrounding starch granules. It is possible that microbial inoculants could improve fermentation, thereby enhancing proteolytic activity in the silo. Additionally, microbial inoculants have potential to reduce or prevent the growth of toxigenic fungi in silage. Therefore, the objective of this study was to determine the effects of storage length and microbial inoculation with heterofermentative and homofermentative inoculants containing Enterococcus faecium on the fermentation profile, N fractions, and ruminal in situ starch disappearance of whole-plant corn silage, as well as the effect of microbial inoculation on silage mycotoxin concentrations. Whole-plant corn (333 ± 10 g of DM/kg as-fed) was ensiled in quintuplicate vacuum pouches untreated (CON) or after the following treatments: E. faecium at 1.5 × 105 cfu/g (EF); Lactobacillus plantarum at 1 × 105 and E. faecium at 5 × 104 cfu/g of fresh forage (LPEF); and L. buchneri and Lactococcus lactis at 1.5 × 105 cfu/g (LBLL). Silos were stored for 0, 30, 60, 90 or 120 d. Silage pH was greater with LBLL compared to the other three treatments (P = 0.005). Total acids were greater with LPEF than EF (P = 0.005). Ammonia-N (expressed as g/kg of N) was greatest with CON compared to the other treatments (P = 0.001). Concentrations of lactic acid were lower, and concentrations of acetic acid were greater with LBLL compared to the other treatments (P = 0.001). An interaction between microbial inoculation and storage length was observed for soluble CP concentrations as well as ruminal in situ starch disappearance (P = 0.001 and P = 0.012, respectively). Soluble CP (expressed as g/kg of CP) was greater with CON compared to the other treatments at d 30 and 90, but not different at d 60 and 120. Ruminal in situ starch disappearance was reduced for CON

A field experiment was conducted at Research farm of Bihar Agricultural University, Sabour (longitude 87o2’42”East and latitude 25o15?40? North at an altitude of 46 meters above mean sea level) with Katarni rice cv Bhagalpur Katarni during kharif season of 2017. The experiment with ten treatments was laid out in Randomized  block design (RBD)  with three  replications. Results revealed that among all the applied organic treatments the maximum microbial population viz., Bacteria, Actinomycetes, Fungi, Azospirillum, PSB and KSB (71.66, 27.33,  57.66, 43.66, 63.00 and 47.66 cfu × 105 g-1 oven dry soil) were recorded with the application of treatment T5 {(75 % N (FYM) basal + 25 % N (V/C) at 25 DAT + Azospirillum  @ 5 kg ha-1  + PSB @ 5 kg ha-1 + KSB @ 5 kg ha-1)} at panicle initiation stage  and similar trend were obtained at harvesting stage. Application of the same treatment significantly increased dehydrogenase activity by 81.62%, 10.80%, 24.86%, 15.66%, 17.83% and 18.91% when compared with application of T1 (RDF), T3 {(100 % N FYM) as basal)}, T7 {(100 % N (GM)}, T8 {(50 % N (GM) + 50 % N (V/C) at 25 DAT)}, T9 {(75 % N (GM) + 25 % N (V/C) at 25 DAT + Azospirillum @ 5 kg ha-1 + PSB @ 5 kg ha-1 + KSB @ 5 kg ha-1)} and  T10 {(75 % N (GM) + 25 % N (V/C) at 25 DAT + Panchagavya on foliar application )}, respectively. Among all organic treatments the maximum grain yield of paddy (27.39 q ha-1) was recorded in treatment T5 {(75 % N (FYM) basal + 25 % N (V/C) at 25 DAT + Azospirillum  @ 5 kg ha-1  + PSB @ 5 kg ha-1 + KSB @ 5 kg ha-1)}. Among all the organic inputs and microbial inoculants, the combined application of 75 % N (FYM) basal + 25 % N (V/C) at 25 DAT + Azospirillum @ 5 kg ha-1 + PSB @ 5 kg ha-1 + KSB @ 5 kg ha-1 was found to be effective in modifying the soil microbial population and microbial community structure and grain yield of scented rice.

Se estudió el efecto de inoculantes microbianos comerciales sobre las características químicas y fermentativas de ensilajes de maíz forrajero con inclusión de residuos de cáscara de maracuyá. Los tratamientos fueron T1: 75% forraje de maíz y 25% cáscara de maracuyá sin inoculo comercial, T2: 75% forraje de maíz y 25% cáscara de maracuyá con inoculo comercial (All Sill®), T3: 75% forraje de maíz y 25% cáscara de maracuyá con inoculo comercial (Lacto Silo®). Se evaluaron las variables: materia seca (MS), materia orgánica (MO), cenizas (C), fibra cruda (FC) proteína bruta (PB) después 30 días de almacenamiento; el pH y temperatura se evaluaron cada 24 horas, durante siete días de exposición aeróbica post-fermentación. El diseño experimental empleado fue completo al azar con seis repeticiones. Los valores nutritivos de los ensilados de forraje de maíz con cáscara de maracuyá demostraron que hubo una ligera diferencia en la ceniza a los 30 días, mientras la temperatura y el pH a las 0, 24, 48, 72, 96, 120, y 144 horas a los 30 de fermentación no presentaron diferencias significativas. El uso de inoculantes bacterianos permite conservar pero no mejorar la calidad del ensilaje., The effect of commercial microbial inoculants on the chemical and fermentative characteristics of forage maize silage including maracuja peel residues was studied. The treatments were: T1: 75% corn fodder and 25% passion fruit husk without commercial inoculum, T2: 75% maize fodder and 25% passion fruit husk with commercial inoculum (All Sill®), T3: 75% corn fodder and 25% maracuja shell with commercial inoculum (Lacto Silo®). The following variables were evaluated: dry matter (DM), organic matter (OM), ash (C), crude fiber (CP) and crude protein (CP) after 30 days storage; pH and temperature were evaluated every 24 hours for seven days of post-fermentation aerobic exposure. The experimental design employed was randomized complete with six replications. The nutritive values of corn forage silage with passion fruit husk there was a slight difference in ash at 30 days. The temperature and pH at 0, 24, 48, 72, 96, 120 and 144 hours at 30 of fermentation did not present statistical differences. The use of bacterial inoculants allows to preserve but not to improve the quality of the silage.

Plant growth-promoting rhizobacteria (PGPR) are studied as complements/alternatives to chemical fertilizers used in agriculture. However, poor information exists on the potential of PGPR from undisturbed ecosystems. Here, we have evaluated the plant growth-promoting (PGP) effect of rhizobacterial consortia from undisturbed Chilean arid ecosystems (Consortium C1) and agro-ecosystems (Consortium C2) on plant biomass production. The PGP effects of C1 and C2 were assayed in wheat seedlings (Triticum aestivum L.) grown in pots under growth chamber conditions and in pots placed in an open greenhouse under natural conditions, using two different Chilean Andisols (Piedras Negras and Freire series) kept either at 30 or 60% of their maximum water holding capacity (MWHC). PGP effects depended on the soil type, MWHC and the growth conditions tested. Although both consortia showed PGB effects in artificial soils relative to controls in growth chambers, only C1 provoked a PGP effect at 60% MWHC in phosphorus-poor soil of the ‘Piedras Negras’ series. At natural conditions, however, only C1 exhibited statistically significant PGP effects at 30% MWHC in ‘Piedras Negras’, yet and most importantly allowed to maintain similar plant biomass as at 60% MWHC. Our results support possible applications of rhizobacterial consortia from arid ecosystems to improve wheat growth in Chilean Andisols under water shortage conditions.

Se estudió el efecto de inoculantes microbianos comerciales sobre las características químicas y fermentativas de ensilajes de maíz forrajero con inclusión de residuos de cáscara de maracuyá. Los tratamientos fueron T1: 75% forraje de maíz y 25% cáscara de maracuyá sin inoculo comercial, T2: 75% forraje de maíz y 25% cáscara de maracuyá con inoculo comercial (All Sill®), T3: 75% forraje de maíz y 25% cáscara de maracuyá con inoculo comercial (Lacto Silo®). Se evaluaron las variables: materia seca (MS), materia orgánica (MO), cenizas (C), fibra cruda (FC) proteína bruta (PB) después 30 días de almacenamiento; el pH y temperatura se evaluaron cada 24 horas, durante siete días de exposición aeróbica post-fermentación. El diseño experimental empleado fue completo al azar con seis repeticiones. Los valores nutritivos de los ensilados de forraje de maíz con cáscara de maracuyá demostraron que hubo una ligera diferencia en la ceniza a los 30 días, mientras la temperatura y el pH a las 0, 24, 48, 72, 96, 120, y 144 horas a los 30 de fermentación no presentaron diferencias significativas. El uso de inoculantes bacterianos permite conservar pero no mejorar la calidad del ensilaje., The effect of commercial microbial inoculants on the chemical and fermentative characteristics of forage maize silage including maracuja peel residues was studied. The treatments were: T1: 75% corn fodder and 25% passion fruit husk without commercial inoculum, T2: 75% maize fodder and 25% passion fruit husk with commercial inoculum (All Sill®), T3: 75% corn fodder and 25% maracuja shell with commercial inoculum (Lacto Silo®). The following variables were evaluated: dry matter (DM), organic matter (OM), ash (C), crude fiber (CP) and crude protein (CP) after 30 days storage; pH and temperature were evaluated every 24 hours for seven days of post-fermentation aerobic exposure. The experimental design employed was randomized complete with six replications. The nutritive values of corn forage silage with passion fruit husk there was a slight difference in ash at 30 days. The temperature and pH at 0, 24, 48, 72, 96, 120 and 144 hours at 30 of fermentation did not present statistical differences. The use of bacterial inoculants allows to preserve but not to improve the quality of the silage.

Se estudió el efecto de inoculantes microbianos comerciales sobre las características químicas y fermentativas de ensilajes de maíz forrajero con inclusión de residuos de cáscara de maracuyá. Los tratamientos fueron T1: 75% forraje de maíz y 25% cáscara de maracuyá sin inoculo comercial, T2: 75% forraje de maíz y 25% cáscara de maracuyá con inoculo comercial (All Sill®), T3: 75% forraje de maíz y 25% cáscara de maracuyá con inoculo comercial (Lacto Silo®). Se evaluaron las variables: materia seca (MS), materia orgánica (MO), cenizas (C), fibra cruda (FC) proteína bruta (PB) después 30 días de almacenamiento; el pH y temperatura se evaluaron cada 24 horas, durante siete días de exposición aeróbica post-fermentación. El diseño experimental empleado fue completo al azar con seis repeticiones. Los valores nutritivos de los ensilados de forraje de maíz con cáscara de maracuyá demostraron que hubo una ligera diferencia en la ceniza a los 30 días, mientras la temperatura y el pH a las 0, 24, 48, 72, 96, 120, y 144 horas a los 30 de fermentación no presentaron diferencias significativas. El uso de inoculantes bacterianos permite conservar pero no mejorar la calidad del ensilaje., The effect of commercial microbial inoculants on the chemical and fermentative characteristics of forage maize silage including maracuja peel residues was studied. The treatments were: T1: 75% corn fodder and 25% passion fruit husk without commercial inoculum, T2: 75% maize fodder and 25% passion fruit husk with commercial inoculum (All Sill®), T3: 75% corn fodder and 25% maracuja shell with commercial inoculum (Lacto Silo®). The following variables were evaluated: dry matter (DM), organic matter (OM), ash (C), crude fiber (CP) and crude protein (CP) after 30 days storage; pH and temperature were evaluated every 24 hours for seven days of post-fermentation aerobic exposure. The experimental design employed was randomized complete with six replications. The nutritive values of corn forage silage with passion fruit husk there was a slight difference in ash at 30 days. The temperature and pH at 0, 24, 48, 72, 96, 120 and 144 hours at 30 of fermentation did not present statistical differences. The use of bacterial inoculants allows to preserve but not to improve the quality of the silage.

This study evaluated the co-inoculation effect of the endophytic selenobacteria Bacillus sp., Klebsiella sp. or Acinetobacter sp. and the arbuscular mycorrhizal (AM) fungus Rhizophagus intraradices on lettuce plants grown under drought conditions. Plants inoculated with bothnmicroorganisms were able to enhance the Se content in their shoots (1 to 6 pg plant-1) and promote macro-and micronutrient uptake. Moreover, the inoculated plants showed significantntolerance to drought stress, as determined by their adaptation to physiological parameters(relative water content and stomatal conductance), increase in photosynthetic pigments (chlorophyll and carotenoids) and improvement inantioxidant enzyme levels (catalase, ascorbate peroxidase and glutathione reductase). The selenobacteria increased the Se content in lettuce plants and enhanced the effect of AM fungus in controlling the antioxidant systems that play a role as elicitors of plant drought responses and improving the nutritional quality and physiological and biochemical processes involved in plant drought tolerance.

With shifting preferences of consumers towards healthier food, organic food demand has been on the rise for the past two decades. This increased demand has created an opportunity for farmers to shift from conventional to organic production. However, there are risks and uncertainties associated with organic farming. The management of an organic farm in the absence of organic-based disease and pest suppressing strategies constrains farmers from adopting organic vegetable production. The use of cover crops to control soil-borne diseases and suppress weeds and other pests has increased because of its sustainable and environmental friendly nature. This study of the economic impact of the cover crops on organic tomato production in the three states Ohio, New York, and Maryland showed mixed results. In Maryland, mixed forage radish and hairy vetch was projected to have a net present value over 15 years that was $1.53 million higher than single species hairy vetch, assuming maximum adoption level of 50 percent. In New York, mixed rye and turnip gave the higher return with a net present value of $2.61 million. In Ohio, the highest projected return was from mixed hay compared to hairy vetch with a net present value of $3.12 million when used without adding compost amendments. In Maryland and New York when bare ground was also used as a control, only mixed forage radish and hairy vetch in Maryland produced better returns compared to bare ground. A probit regression assessing the factors affecting the decision to adopt mixed species green manure technology indicated that farmer experiences in organic production, farmer age, access to the internet access, and farmers’ perceptions about the benefits of using mixed species green manures were significant factors. Each variables and factors except age had a positive influence. Similarly, probit results for microbial inoculants indicated that education, gender, and access to the internet were significant determinants, and had a negat

This study evaluated the effects of two bacterial inoculants on the fermentation quality and aerobic stability of ensiled potato hash (PH) and on digestibility, growth performance and carcass characteristics of growing pigs fed the ensiled PH. In the first experiment, 700 grams of PH, was mixed with 300g wheat bran (as is basis) and ensiled in 1.5 litre anaerobic jars. The mixture had a dry matter (DM) of 41.3 g/kg, 78.05 g/kg DM of water-soluble carbohydrates (WSC) and a pH of 6.87 at day 0 and was treated with Bonsilage forte, BF, a heterofermentative LAB, Lalsil Fresh lactobacillus bachneri, LFLB, a homofermentative LAB or without LAB inoculant (control). Triplicate samples per treatment were collected on days 0, 3, 10, 21 and 45 post-ensiling and analysed for DM, WSC, pH, lactic acid (LA), acetic acid (AA), butyric acid (BA), propionic acid (PA) and ammonia-N. On day 45, the silage was subjected to aerobic exposure for 5 days and CO2 production was measured. In the second and third experiments, potato hash-wheat bran mixtures of 7:3 ratio were produced and ensiled in 210 litre drums that were kept at a 250C environment. The second experiment involved an apparent nutrients digestibility study using 30 female (Large White x Landrace crossbred) pigs (30 2 kg live weight), which were selected and housed individually. A cross-over design was applied with two periods and 30 animals fed 10 diets. Three pigs were given one diet per period. The diets were: commercial feed (control); 20, 40, and 60% dietary inclusion of potato hash silage (untreated potato hash silage, UPHS; Lalsil Fresh treated potato hash silage, LFLBPHS, and Bonsilage forte treated potato hash silage, BFPHS). Each experimental period lasted for eleven days with seven days being for adaptation to each diet and four days for collection of faeces before crossing over to the next treatment. Pigs were fed twice per day at 8:00 and 15:00, with the daily allowance equally divided between the two meals. Faec

This study evaluated the effects of two bacterial inoculants on the fermentation quality and aerobic stability of ensiled potato hash (PH) and on digestibility, growth performance and carcass characteristics of growing pigs fed the ensiled PH. In the first experiment, 700 grams of PH, was mixed with 300g wheat bran (as is basis) and ensiled in 1.5 litre anaerobic jars. The mixture had a dry matter (DM) of 41.3 g/kg, 78.05 g/kg DM of water-soluble carbohydrates (WSC) and a pH of 6.87 at day 0 and was treated with Bonsilage forte, BF, a heterofermentative LAB, Lalsil Fresh lactobacillus bachneri, LFLB, a homofermentative LAB or without LAB inoculant (control). Triplicate samples per treatment were collected on days 0, 3, 10, 21 and 45 post-ensiling and analysed for DM, WSC, pH, lactic acid (LA), acetic acid (AA), butyric acid (BA), propionic acid (PA) and ammonia-N. On day 45, the silage was subjected to aerobic exposure for 5 days and CO2 production was measured. In the second and third experiments, potato hash-wheat bran mixtures of 7:3 ratio were produced and ensiled in 210 litre drums that were kept at a 250C environment. The second experiment involved an apparent nutrients digestibility study using 30 female (Large White x Landrace crossbred) pigs (30 2 kg live weight), which were selected and housed individually. A cross-over design was applied with two periods and 30 animals fed 10 diets. Three pigs were given one diet per period. The diets were: commercial feed (control); 20, 40, and 60% dietary inclusion of potato hash silage (untreated potato hash silage, UPHS; Lalsil Fresh treated potato hash silage, LFLBPHS, and Bonsilage forte treated potato hash silage, BFPHS). Each experimental period lasted for eleven days with seven days being for adaptation to each diet and four days for collection of faeces before crossing over to the next treatment. Pigs were fed twice per day at 8:00 and 15:00, with the daily allowance equally divided between the two meals. Faec

Includes bibliographical references (leaves 79-89)., Includes abstract.

Includes bibliographical references (leaves 79-89)., Includes abstract.

English: Techniques to maintain and preserve microorganisms have become important to ensure availability of microorganisms for application in many institutions and processes. Several methods are available to preserve microorganisms and include drying, lyophilization, cryopreservation and sub-culturing. Many of these methods, may lead to population change through selection, loss of viability as well as poor survival rates when used for maintenance of yeasts. In this study, different preservation methods (cryopreservation at -196°C in liquid nitrogen, freezing at -70°C and lyophilization) were compared in the maintenance of brewing inocula over a period of two years. Interestingly, a decrease in the percentage of variants and respiratory deficient yeasts (RDs) was generally found when preserved through cryopreservation (-196°C) and freezing (-70°C). In contrast, the percentage variants when revived yeasts were grown in wort, increased in yeasts maintained through lyophilization. A high percentage viable cells (>95%) was recorded for yeast cultures maintained at -196°C and at -70°C while viability was low (<50%) when maintained through lyophilization. Consequently, the maintenance methods of choice are cryopreservation and freezing. The developed cryopreservation method was successfully implemented in the brewing process that produced the champion lager beer "Castle Lager" at Burton-upon-Trent in the UK (April; 2000). The results of the estimate of the components of variance showed that the largest source of variation in all three of the methods tested, was the error arising from the analytical test. On the basis of these results, it , subsequently became another aim of this study to explore alternative analytical tests to differentiate and characterise yeasts in the brewing industry. Consequently, PCR based RFLP, fatty acid and sterol profiles were evaluated. Using PCR based RFLP, a study to differentiate brewing yeasts from related yeasts using amplification and rest, Afrikaans: Tegnieke vir die bewaring van mikrobes is belangrik ten einde die beskikbaarheid van mikrobes vir aanwending in verskeie instansies en prosesse te verseker. Verskeie metodes vir die bewaring van mikrobes is beskikbaar en sluit in droging, vriesdroging, 'vries en die maak van subkulture. As hierdie metodes gebruik word vir die bewaring van giste, mag van hulle lei tot veranderinge in die populasie a.g.v. seleksie, verlies aan lewensvatbaarheid en lae oorlewingsvlakke. In hierdie studie is verskillende bewaringsmetodes (vries by (-196°Cin vloeibare stikstof, vries by -70°C en vriesdroging) vergelyk oor 'n tydperk van twee jaar in die bewaring van brou-inokula. Oor die algemeen is 'n afname in variante en respiratories-gebrekkige giste gevind as bewaring d.m.v. vriesing (-196°C en -70°C) gedoen is. In teenstelling, het die persentasie variante toegeneem as gevriesdroogde giste weer in moutekstrak opgegroei is. 'n Hoë persentasie lewensvatbare selle (>95%) is waargeneem in giskulture bewaar by -196°C en -70°C, terwyl lewensvatbaarheid laag was <50%) in gevriesdroogde kulture. Gevolglik is die beste bewaringsmetodes vriesing. Die ontwikkelde vriesingsmetodes is suksesvol geïmplementeer in die brouproses wat gelei het tot die produksie en kroning van die kampioen lager "Castle lager" by Burton-upon-Trent in die VK (April, 2000). Die resultate van die berekening van variasiekomponente het getoon dat die grootste bron van variasie in al drie die getoetste metodes, die fout a.g.v. die analitiese metode was. Op grond van hierdie resultate, het dit 'n verdere doel van die studie geword om ondersoek in te stel na alternatiewe analitiese metodes om giste in die brou-industrie te differensieer en te karakteriseer. Gevolglik is PKR gebaseerde RFLP, vetsuur- en sterolprofiele geëvalueer. Met behulp van 'n PKR gebaseerde RFLP, is 'n studie uitgevoer om brouersgiste van verwante giste te onderskei m.b.V. amplifisering en beperkings-polimorfisme van die ITS areas. Onderskei