Production of the postharvest biocontrol agent Bacillus subtilis CPA-8 using low cost commercial products and by-products

The aim of this research was to identify a low cost medium based on commercial products and by-products that provided maximum Bacillus subtilis CPA-8 growth and maintained biocontrol efficacy. Low cost media combining economical nitrogen and carbon sources such as yeast extract, peptone, soy products, sucrose, maltose and molasses were tested. Tests were carried out in 250-ml flasks containing 50 ml of each tested medium. Maximum cell growth (>3 × 10⁹ CFU ml^?1) was obtained in defatted soy flour 44% combined with sucrose or molasses media. Second, CPA-8 production was scaled up in a 5-l fermenter and CPA-8 population dynamics, pH and oxygen consumption in the optimized medium (defatted soy flour 44% – molasses) was recorded. In these tests, there was a 5-h lag phase before growth, after which exponential growth occurred and maximum production was 3 × 10⁹ CFU ml^?1 after 20 h. Fruit trials with cells and cell free supernatants from CPA-8 grown in optimized medium maintained biocontrol efficacy against Monilinia fructicola on peaches, resulting in disease reductions up to 95%. CPA-8 populations survived in wounds on inoculated peaches, regardless of the culture media used. The results show that B. subtilis CPA-8 can be produced in a low cost medium combining inexpensive nitrogen and carbon sources (40 g l^?1 defatted soy flour 44%, 5 g l^?1 molasses plus mineral trace supplements) in shake flasks and a laboratory fermenter (5 l). The results could be used to provide a reliable basis for scaling up the fermentation process to an industrial level.     

Efficacy of the antagonist Aureobasidium pullulans PL5 against postharvest pathogens of peach,apple and plum and its modes of action

The efficacy of Aureobasidium pullulans PL5 against different postharvest pathogens of fruits (Monilinia laxa on plums and peaches, Botrytis cinerea and Penicillium expansum on apples) were evaluated under storage conditions when applied at 10⁸ cells ml⁻¹ and their interactions were studied in vitro and in vivo to discover the possible modes of action. Under 1.2 °C and 95% relative humidity (RH) for 28 days, the efficacy of PL5 against M. laxa on plums was 45%, reducing disease incidence from 78% to 43%. Under 1 °C and 95% RH for 21 days, the efficacy against M. laxa on peaches was 63%, reducing disease incidence from 79% to 29%. Under 4 °C and 95% RH for 45 days, the efficacy against B. cinerea and P. expansum on apples was 56% and 46%, respectively. In Lilly–Barnett minimal salt medium with the fungal cell walls of pathogens as sole carbon source, PL5 produced β-1,3-glucanase, exo-chitinase and endo-chitinase. Nutrient concentrations had significant effect on pathogen growth reduction by PL5. No attachment was observed in antagonist–pathogen interactions in vitro or in vivo. PL5 completely inhibited pathogen spore germination in PDB at 10⁸ cells ml⁻¹, whereas at 10⁶ cells ml⁻¹ the efficacy was significantly decreased. However, inactivated cells and culture filtrate of PL5 had no effect on pathogen spore germination and germ tube elongation. Our results showed that A. pullulans PL5 could be introduced in commercial formulations to control postharvest pathogens on fruits and its activity was based on secretion of lytic enzymes and competition for nutrients.     

Field applications of improved formulations of Candida sake CPA-1 for control of Botrytis cinerea in grapes

There is increasing interest in the use of biological control agents (BCAs) to replace synthetic fungicides. The aim of this study was to evaluate the effectiveness of combining different formulation strategies on the establishment, survival, persistence and efficacy of Candida sake CPA-1 applied in the field in order to control Botrytis cinerea in grapes. Different formulations of C. sake cells were applied at flowering, pea sized berries, veraison and before harvest. In 2005, heat adapted or non-adapted fresh cells of C. sake were tested. In 2006, these same treatments were tested but, in this case, the C. sake cells were also formulated in an isotonic solution. The compound Fungicover® (FC) an edible coating was evaluated as a potential additive for C. sake treatments. Spray applications of different formulations of C. sake resulted in colonisation of bunches under field conditions and when combined with FC, C. sake had significantly higher survival rates (up to 50% higher) compared with C. sake without additive FC. Formulation of C. sake cells in an isotonic solution combined with FC resulted in Botrytis spp. control similarly than fungicide treatment. The potential of C. sake for biocontrol of Botrytis bunch rot of grapevine has been demonstrated. FC has a beneficial effect on the BCA, improving the persistence of C. sake cells on the host and its efficacy to levels comparable to fungicide treatment. It is possible to broaden the spectrum of use of BCAs using different formulation strategies and to thereby develop practical uses under field conditions.     

Microencapsulation of Bacillus subtilis B99-2 and its biocontrol efficiency against Rhizoctonia solani in tomato

Biological control is a promising approach to protecting plants from disease. Bacillus subtilis has been widely used in agriculture for promoting plant growth and biocontrol. However, their short shelf life limits the application of biological pesticides. The objectives of this study were to develop a microencapsulation procedure of B. subtilis B99-2 using maltodextrin and gum arabic as wall materials to determine the optimum conditions of spray-drying in microencapsulation, evaluate storage stability of microcapsules, and assess their biocontrol efficiency against Rhizoctonia solani in tomato under field conditions. We microencapsulated the Bacillus thallus by spray-drying with various concentrations of the wall material. Maltodextrin was found to be an efficient wall material, especially at concentrations higher than 80%, while gum arabic did not affect the bacterial survival rate. The mean survival rate of B. subtilis was more than 90%, when spray drying was performed at 145 °C, with a feed flow rate of 550 mL h⁻¹, and a spray pressure of 0.15 MPa. B. subtilis microcapsule survival rate was 87.53% after 540 d of storage, which was a longer shelf life than that of wettable powders. Moreover, its biocontrol efficacy reached 79.91% when a dosage of 300 g hm⁻² was used, the microcapsule showed higher control efficacy than Thiram wettable powder against R. solani in tomato under field conditions. All these characteristics indicated that B. subtilis microcapsules have the potential to become a successful biocontrol product.     

Efficacy assessment of Pichia guilliermondii strain Z1, a new biocontrol agent,against citrus blue mould in Morocco under the influence of temperature and relative humidity

The interactions of Penicillium italicum, which causes blue mould, and antagonistic yeast Pichia guilliermondii strain Z1 were examined in controlled environments, to determine the influence of relative humidity (RH) (45%, 75%, 85%, 98%, and 100%) and temperature (T) (5, 10, 15, 20, and 25 °C). All main effects and interactions were significant (P ? 0.05), with the exception of interactions RH×T and strain Z1 (BCA)×RH×T. In the pathogen control, the lesion diameter of blue mould developed under all environmental conditions but was the largest at a RH range between 98% and 100%, independent of the temperature. The efficacy of strain Z1 appeared to be independent of the environment and reduced disease incidence by more than 85% in all environmental conditions. Rapid colonization of the antagonistic yeast strain Z1 on citrus wounded sites was recorded during the first week at 5 °C. Colonization then stabilized at ±6.9 × 10⁶ CFU/ml for 30 days. This indicates that P. guilliermondii is able to adapt itself and colonize the wound sites prior to the arrival of the pathogen, displaying greater efficiency than when colonizing wounds after pathogen. The antagonist was capable of growing in low concentrations of orange juice (0.1–5%), with greatest growth at 5%. Applying strain Z1 (1 × 10⁸ CFU/ml) as a formulated product significantly reduced the incidence of infected fruits and the percentage of infected wounds relative to the pathogen control. Disease control with formulated product (45%) was slightly lower than that obtained with thiabendazole (20%) or strain Z1 culturable cells (25%). These results suggest that strain Z1 may be a useful BCA for control of blue mould under varying environmental conditions, and control may be enhanced by combining with other eco-friendly post-harvest treatments or improved formulation.     

The importance of relative humidity and trophic resources in governing ecological niche of the invasive carabid beetle Merizodus soledadinus in the Kerguelen archipelago

Comprehensive studies to identify species-specific drivers of survival to environmental stress, reproduction, growth, and recruitment are vital to gaining a better understanding of the main ecological factors shaping species habitat distribution and dispersal routes. The present study performed a field-based assessment of habitat distribution in the invasive carabid beetle Merizodus soledadinus for the Kerguelen archipelago. The results emphasised humid habitats as a key element of the insect’s realised niche. In addition, insects faced food and water stress during dispersal events. We evaluated quantitatively how water availability and trophic resources governed the spatial distribution of this invasive predatory insect at Îles Kerguelen. Food and water stress survival durations [in 100%, 70%, and 30% relative humidity (RH) conditions] and changes in a set of primary metabolic compounds (metabolomics) were determined. Adult M. soledadinus supplied with water ad libitum were highly tolerant to prolonged starvation (LT₅₀ = 51.7 ± 6.2 d). However, food-deprived insect survival decreased rapidly in moderate (70% RH, LT₅₀ = 30.37 ± 1.39 h) and low (30% RH, LT₅₀ = 13.03 ± 0.48 h) RH conditions. Consistently, body water content decreased rapidly in insects exposed to 70% and 30% RH. Metabolic variation evidenced the effects of food deprivation in control insects (exposed to 100% RH), which exhibited a progressive decline of most glycolytic sugars and tricarboxylic acid cycle intermediates. Most metabolite levels were elevated levels during the first few hours of exposure to 30% and 70% RH. Augmented alanine and lactate levels suggested a shift to anaerobic metabolism. Simultaneously, peaks in threonine and glycolytic sugars pointed to metabolic disruption and a progressive physiological breakdown in dehydrating individuals. Overall, the results of our study indicate that the geographic distribution of M. soledadinus populations is highly dependent on habitat RH and water accessibility.     

Production of lactic acid from soybean stalk hydrolysate with Lactobacillus sake and Lactobacillus casei

In order to make full use of soybean stalk produced in large quantity annually in China, a process is proposed for production of lactic acid from soybean stalk hydrolysate with Lactobacillus sake and Lactobacillus casei. Experiments were conducted using the proposed process and experimental results indicate that the potential of 242 mg (g stalk)⁻¹ fermentable sugar is released from hydrolysate through enzymatic saccharication with a saccharication of 51%. The main sugar released from pretreated soybean stalk through enzymatic hydrolysis was a mixture of glucose, xylose and cellobiose at a ratio of 3.9:1.7:1. Fermentation of soybean stalk hydrolysate by L. sake and L. casei yielded the lactic acid conversion of 48% and 56%, respectively, however, lactic acid conversion increased to 71% by co-inoculation of both strains. L. sake and L. casei were able to degrade glucose, but unable to completely assimilate xylose and cellobiose. The proposed process can be used to produce lactic acid from soybean stalk hydrolysate.     

Braking characteristics during cutting and pivoting in female soccer players

Most biomechanical studies into changing direction focus on final contact (FC), whilst limited research has examined penultimate contact (PEN). The aim of this study was to explore the kinematic and kinetic differences between PEN and FC of cutting and pivoting in 22 female soccer players (mean ± SD; age: 21 ± 3.1 years, height: 1.68 ± 0.07 m, mass: 58.9 ± 7.3 kg). Furthermore, the study investigated whether horizontal force–time characteristics during PEN were related to peak knee abduction moments during FC. Three dimensional motion analyses of cutting and pivoting on the right leg were performed using Qualysis ‘Proreflex’ infrared cameras (240 Hz). Ground reaction forces (GRF) were collected from two AMTI force platforms (1200 Hz) to examine PEN and FC. Both manoeuvres involved significantly (P < 0.05) greater knee joint flexion angles, peak horizontal GRF, but lower average horizontal GRF during PEN compared to FC. Average horizontal GRF during PEN (R = −0.569, R² = 32%, P = 0.006) and average horizontal GRF ratio (R = 0.466, R² = 22%, P = 0.029) were significantly related to peak knee abduction moments during the FC of cutting and pivoting, respectively. The results indicate PEN during pre-planned changing direction helps reduce loading on the turning leg where there is greater risk of injuries to knee ligaments.     

Two-sex life table and predation rate of Cybocephalus flavocapitis Smith (Coleoptera: Cybocephalidae) reared on Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae), in Taiwan

Development, survival, and fecundity of the predator, Cybocephalus flavocapitis Smith, reared on its host Aulacaspis yasumatsui Takagi, were studied at 24 °C, 70 ± 10% RH, and photoperiod of 12:12 (L:D) h under laboratory conditions. Developmental periods for egg, larval, and pupal stages were 6.4, 12.1 and 14.3 d, respectively. The mean longevity of adults was 85.1 d. Raw life history data of all individuals were pooled and analyzed according to the age-stage, two-sex life table theory. The intrinsic rate of increase (r) was 0.05 d^? 1, the finite rate of increase (λ) was 1.05 d^? 1, the net reproductive rate (R₀) was 29.1 offspring, and the mean generation time (T) was 63.3 d. When we incorporated the age-stage variability of predation rate with the two-sex life table, our results indicated that the predation rates of larvae and adults were 743 eggs and 1595 scales, respectively. The net predation rate of C. flavocapitis is 1874 scales. Additionally, we compared life table results of C. flavocapitis with those of a previous life table study on Cybocephalus nipponicus because both species are currently used for the biological control of A. yasumatsui in Taiwan.     

Influence of climatic conditions and industrial emissions on spruce tree-ring Pb isotopes analyzed at ppb concentrations in the Athabasca oil sands region

This study investigates Pb isotope ratios at low concentrations (parts per billion; ppb) in tree rings and soils in the Northern Athabasca Oil Sands Region (NAOSR), western Canada, to evaluate if: (1) climatic conditions influence on tree-ring Pb assimilation; and (2) such low Pb content allows inferring the regional Pb depositional history.Our results reflect the influence of winter snow cover and the importance of minimum temperature and precipitation in spring and summer on the bioavailability of Pb and its passive assimilation by trees in sub-arctic semi-humid climatic conditions. Winter conditions can influence the state of root systems that subsequently impacts the following growth period, while spring and summer conditions likely control microbial processes and water source, and may thus impact Pb assimilation by trees. Thus, the results of tree-ring Pb concentrations show interesting correlation with cumulated snow from November of the previous year to February (ρ = 0.53; P < 0.01; n = 36). Likewise, the ²⁰⁶Pb/²⁰⁷Pb ratios inversely correlate with minimum temperature from April to September (ρ = −0.67; P < 0.01; n = 40) and precipitation from May to August (ρ = −0.42; P < 0.01; n = 36). The isotopic results also suggest that the effects of climatic variations are superimposed by regional industrial Pb deposition: Western North American Aerosols (WNAA) and fugitive dust from the oil sands mining operations appear to be the most likely sources.Importantly, this study suggests that even at low Pb concentrations, tree-ring Pb isotopes are modulated by climatic conditions and potential input of regional and long-range transport of airborne Pb. These interpretations open the possibility of using Pb isotopes as an environmental tool for inferring the pollution history in remote regions, and improving our understanding of its natural cycle through the forest environment.     

Life table of cycad scale,Aulacaspis yasumatsui (Hemiptera: Diaspididae), reared on Cycas in Taiwan

Aulacaspis yasumatsui Takagi (Hemiptera: Diaspididae), an invasive scale insect, attacks different species of Cycas (Cycadales: Cycadaceae) in Taiwan. Development, survival and fecundity of A. yasumatsui were studied on Cycas taitungensis at 24 °C, 70 ± 10% RH, and a photoperiod of 12:12 (L:D) h under laboratory conditions. Data on the life history of A. yasumatsui were analyzed using the age-stage, two-sex life table, to address variable development rates among individuals and between sexes. The egg incubation time was 7.26 days for both females and males and female nymphal development duration was 28.65 days. The development duration of male nymphal stages + pupal stage was 19 days. The total pre-oviposition period (TPOP) was 35.92 days. The maximum longevity of female adults was 67 days and 1 day for males. The intrinsic rate of increase (r) was 0.100 day^-1, the finite rate of increase (λ) was 1.11 day^-1, the net reproduction rate (R_o) was 111.51 offspring /individual, and the mean generation time (T) was 47.24 day. Life table data can be used to project population growth, to design mass rearing programs and to establish management tactics to control insect pests.     

Differential changes of neuroactive amino acids in samples obtained from discrete rat brain regions after systemic administration of saxitoxin

Aspartic acid, glutamic acid, γ-amino-n-butyric acid (GABA) and 2-aminoethanesulfonic acid are neuroactive amino acids. They are found in the central rat nervous system. Here, we have studied if a relationship exists between the presence of saxitoxin (STX) a paralytic poisoning shellfish (PSP) and the neuroactive amino acids. Samples of striatum (S), hypothalamus (H), mid brain (MB), frontal cortex (FC), brain stem (BS), right hemisphere (RH) and left hemisphere (LH) of rat brain were collected and analyzed for neuroactive amino acids (AAn_t) by Aswad method (1984). Experiments, consisting of intraperitoneal injection of SXT (5 and 10 μg kg^?1 body weight) to young male rats, evoked significant changes in AAn_t above basal values. Aspartic and glutamic acid significantly increased for RH and LH (after 30 min the increased was 116% and 210%, P ≤ 0.001 over basal values, respectively). On the other hand, aspartic, glutamic, taurine and GABA significantly decreased for S (after 30 min the decreased was 77.4%; 84%; 93.8% and 95.3%, P ≤ 0.001 over basal values, respectively). These results suggest that STX alters AAn_t. It is produced at least in part, because STX blocks voltage-gated sodium channels and this blockade could decrease AAn_t release by exocytotic dependent mechanism of depolarization.     

Biocontrol of major postharvest pathogens on apple using Rhodotorula glutinis and its effects on postharvest quality parameters

The biocontrol activity of Rhodotorula glutinis on gray mold decay and blue mold decay of apple caused by Botrytis cinerea and Penicillium expansum, respectively, was investigated, as well as its effects on postharvest quality of apple fruits. The results show there was a significant negative correlation between concentrations of the yeast cells and the disease incidence of the pathogens. The higher concentration of the R. glutinis, the better effect of the biocontrol capacity. At concentrations of R. glutinis 1 × 10⁸ CFU ml^?1, the amount of gray mold decay was completely inhibited after 5 days incubation at 20 °C, after challenge with B. cinerea spores suspension of 1 × 10⁵ spores ml^?1; While the blue mold decay was completely inhibited at concentrations of 5 × 10⁸ CFU ml^?1, at challenged with P. expansum spores suspension of 5 × 10⁴ spores ml^?1_. These results demonstrated that the efficacy of R. glutinis in controlling of gray mold decay of apples was better than the efficacy of controlling blue mold. R. glutinis within inoculated wounds on apples increased in numbers at 20 °C from an initial level of 9.5 × 10⁵ CFU per wound to 2.24 × 10⁷ CFU at 20 °C after 1 day. The highest population of the yeast was recovered 4 days after inoculation, the yeast population in wounds increased by 56.9 times. After that, the population of the yeast began to decline very slowly. R. glutinis significantly reduced the incidence of natural infections on intact fruit from 75% in the control fruit to 28.3% after 5 days at 20 °C, and from 58.3 to 6.7% after 30 days at 4 °C followed by 4 days at 20 °C. R. glutinis treatment had no deleterious effect on quality parameters after 5 days at 20 °C or after 30 days at 4 °C followed by 4 days at 20 °C.     

Effective control of <Emphasis Type="Italic">Botrytis</Emphasis> bunch rot in commercial vineyards by large-scale application of <Emphasis Type="Italic">Candida sake</Emphasis> CPA-1

Biological control with microorganisms is regarded as a promising control strategy against Botrytis bunch rot (BBR, grey mould) on grapes. Candida sake CPA-1 is a yeast that has previously shown a high efficacy against BBR in small-scale field trials. The present work aims to confirm this efficacy in commercial conditions and to evaluate the compatibility of C. sake with phytosanitary products that are commonly used in viticulture. The large-scale spray programmes (two to three applications in the growing season) were carried out in three field sites in Catalonia, North-East Spain, with different vineyard management styles. The overall reductions were in the ranges of 35 ± 5.7 to 64 ± 3.7% incidence, and 39 ± 17.5 to 85 ± 3.9% severity, compared to the control. Only four out of 39 phytosanitary products, tested in liquid suspension with C. sake, were incompatible with the yeast. The results demonstrated the potential of C. sake to become a reliable solution as a biocontrol product to be integrated in the control of BBR within the future.     

Design,synthesis, and cholesterol-lowering efficacy for prodrugs of berberrubine

In order to enhance oral bioavailability of berberine (BBR) for its cholesterol-lowering efficacy in vivo, a series of ester or ether prodrugs of berberrubine (M1), which is an active metabolite of BBR after first-pass metabolism, were designed, semi-synthesized, and evaluated. Among these M1 prodrugs, compound 5g possessing palmitate at the 9-position showed a moderate Log P value and esterase hydrolysis rate for releasing M1 in blood. Its cholesterol-lowering efficacy in vivo was evaluated in hyperlipidemic SD rats. Compound 5g (100 mg/kg/d) reduced blood CHO and LDL-c by 35.8% and 45.5%, respectively, similar to that by BBR. It also exhibited a good safety in rats with no side-effect on liver and kidney function. Therefore, the design of M1 prodrug appears to be an effective strategy to improve pharmacokinetic feature of BBR for its lipid-lowering efficacy in vivo.     

Evaluation of biological seed treatments in combination with management practices for the control of Fusarium dry rot of potato

Seed-borne diseases of potato represent a significant constraint to potato production in the US. The use of an effective fungicide in combination with good management practices during cutting and storage, prior to planting, is essential to reducing disease. The efficacy of two biocontrol agents (Bacillus subtilis and Trichoderma harzianum), and a commercially formulated mixture of the chemicals fludioxonil plus mancozeb, applied as seed treatments in combination with different management practices, were evaluated over two years for the control of seed piece decay and sprout rot caused by Fusarium sambucinum. Treatments were made 10 days prior to planting and at planting, and tubers were re-stored at either 18 °C and 95% RH with forced air ventilation at 5950 l min⁻¹ (optimal conditions), at 25 °C in the dark without ventilation (sub-optimal), or not stored at all prior to planting. Seed piece and sprout health were evaluated in vitro and agronomic impacts evaluated in field experiments. Results showed that the biological control agents B. subtilis and T. harzianum provided good control of sprout rot and seed piece decay caused by F. sambucinum, when seed was re-stored under optimal conditions or not re-stored at all. Under optimal conditions, treatment with B. subtilis reduced sprout rot and seed piece decay on average by 66% and 84%, respectively. Treatment with T. harzianum reduced sprout rot and seed piece decay on average by 70% and 81%, respectively. Treatment with fludioxonil + mancozeb reduced sprout rot and seed piece decay under both re-storage regimes. Under optimal conditions, disease incidence and severity was reduced on average by 81% and 97%, respectively. Neither biological control agent reduced seed piece decay incidence under either re-storage regime compared to the untreated controls.     

Response of native grasses and Cicer arietinum to soil polluted with mining wastes: Implications for the management of land adjacent to mine sites

Mine tailings are an environmental problem in Southern Spain because wind and water erosion of bare surfaces results in the dispersal of toxic metals over nearby urban or agricultural areas. Revegetation with tolerant native species may reduce this risk. We grew two grasses, Lygeum spartum and Piptatherum miliaceum, and the crop species Cicer arietinum (chickpea) under controlled conditions in pots containing a mine tailings mixed into non-polluted soil to give treatments of 0%, 25%, 50%, 75% and 100% mine tailings. We tested a neutral (pH 7.4) mine tailings which contained high concentrations of Cd, Cu, Pb and Zn. Water-extractable metal concentrations increased in proportion to the amount of tailings added. The biomass of the two grasses decreased in proportion to the rate of neutral mine-tailing addition, while the biomass of C. arietinum only decreased in relation to the control treatment. Neutron radiography revealed that root development of C. arietinum was perturbed in soil amended with the neutral tailings compared to those of the control treatment, despite a lack of toxicity symptoms in the shoots. In all treatments and for all metals, the plants accumulated higher concentrations in the roots than in shoots. The highest concentrations occurred in the roots of P. miliaceum (2500 mg kg^?1 Pb, 146 mg kg^?1 Cd, 185 mg kg^?1 Cu, 2700 mg kg^?1 Zn). C. arietinum seeds had normal concentrations of Zn (70–90 mg kg^?1) and Cu (6–9 mg kg^?1). However, the Cd concentration in this species was ～1 mg kg^?1 in the seeds and 14.5 mg kg^?1 in shoots. Consumption of these plant species by cattle and wild fauna may present a risk of toxic metals entering the food chain.     

Alginate embedding and subsequent sporulation of in vitro-produced Conidiobolus thromboides hyphae using a pressurised air-extrusion method

Conidiobolus thromboides is an entomophthoralean fungus with potential as a biological control agent of aphids. However, its application in biological control is limited due to its formulation requirements. The objective of this study was to develop and optimise a novel air-extrusion method to embed C. thromboides hyphae at high density in alginate pellets. An orthogonal experimental design was used to investigate selected combinations of parameters known to affect hyphal density within pellets. The diameter of pellets produced, and the calculated density of hyphae within them, ranged from 0.18 ± 0.09 to 3.17 ± 0.06 mm and from 0.02 to 350.56 mg/mm³ respectively. These data were used to predict the optimal parameter combination to deliver the greatest density of hyphae of C. thromboides per pellet: 1% sodium alginate, a 1:2 ratio of hyphae to sodium alginate, an orifice diameter of 0.232 mm and an air pressure of 0.05 MPa. Pellets made under the optimal conditions predicted produced a mean total of 4.3 ± 0.6 × 10⁵ conidia per pellet at 100% relative humidity which was significantly greater than the mean total number of conidia produced from infected aphid cadavers of comparable size (9.35 ± 0.85 × 10⁴) (p < 0.001). In conclusion, air-extrusion embedding appears to be a promising method for formulating in vitro-produced hyphae of C. thromboides for use in biological control.     

Differentiated influence of off-road and on-road cycling practice on balance control and the related-neurosensory organization

This study aimed to determine the sensorimotor strategies privileged by mountain bikers (MTB) and road cyclists (RC) for balance control. Twenty-four MTB and 24 RC (off-road Olympics, world, continental and national champions, Tour-de-France participants, on-road world cup race winner) volunteered to answer a questionnaire about the characteristics of cycling practice and perform a sensory organization test, aiming to evaluate balance control in 6 different sensory situations based upon visual and support surface perturbations (C1^ES to C6^ES). RC balance performances were better than those of MTB both during quiet stance eyes opened (C1^ES, p = 0.011) and when only somatosensory information is disrupted (C4^ES, p = 0.039), highlighting a higher use of vision to control balance in RC. Moreover, a positive correlation was shown in the whole population (MTB + RC) between the visual ratio (R^VIS = C4^ES/C1^ES) and the proportion of riding distance of on-road cycling (ρ = 0.28, p = 0.054). In MTB, the use of proprioception (somatosensory ratio: R^SOM = C2^{ES(eyes closed)}/C1^ES) was increased by a higher intensity of off-road cycling (ρ = 0.49, p = 0.018) and that of vision (R^VIS) by a higher intensity of on-road cycling (ρ = 0.41, p = 0.048). The difference in sensory organization between MTB and RC could be explained by adaptive processes elaborated from environmental stimulations and technical specificities of these disciplines.     

Effects of dietary supplementation of Lactobacillus pentosus PL11 on the growth performance,immune and antioxidant systems of Japanese eel Anguilla japonica challenged with Edwardsiella tarda

The aim of this study was to determine the efficacy of dietary administration of Lactobacillus pentosus PL11 on growth performance and the immune and antioxidant systems in Japanese eel Anguilla japonica challenged with Edwardsiella tarda. A total of 75 Japanese eels (24.63 ± 0.83 g) were grouped into 5 treatment diets which were a control diet (C) without E. tarda and 4 treatment diets with E. tarda challenge, including C for E. tarda challenge (NC), C plus L. pentosus PL11 supplemented diet (10⁸ cfu g^?1) (T-PL11), C plus L. pentosus KCCM 40997 supplemented diet (10⁸ cfu g^?1) (T-Lp) and C plus Weissella hellenica DS-12 supplemented diet (10⁸ cfu g^?1) (T-Wh) for 5 weeks (4 week before and 1 week after challenge). The results showed enhanced growth performance in fish fed the diet containing L. pentosus PL11 compared to others. The growth performance parameters including specific growth rate (SGR) and weight gain (WG), feed intake (FI), feed conversion ratio (FCR) and survival were significantly (P < 0.05) higher in fish maintained on L. pentosus PL11 supplemented diet compared to C and NC. T-PL11 group also shows a significant increase in the levels of plasma immunoglobulin M, CAT and SOD activities compared to NC. Hematological parameters and mieloperoxidase were significantly better in fish fed the L. pentosus PL11 supplemented diet than in the control. L. pentosus PL11 supplementation recover the reduced expression of SOD, CAT and heat shock protein 70 genes in liver and intestine in pathogen challenged fishes. In conclusion the result of the current study demonstrated L. pentosus PL11 potential as an alternative to antibiotic supplementation to improve the growth and health performance of Japanese eel (A. japonica).