The Ability of a Novel Strain Scheffersomyces (Syn. Candida) shehatae Isolated from Rotten Wood to Produce Arabitol

Arabitol is a polyalcohol which has about 70% of the sweetness of sucrose and an energy density of 0.2 kcal/g. Similarly to xylitol, it can be used in the food and pharmaceutical industries as a natural sweetener, a texturing agent, a dental caries reducer, and a humectant. Bio­technological production of arabitol from sugars represents an interesting alternative to chemical production. The yeast Scheffersomyces shehatae strain 20BM-3 isolated from rotten wood was screened for its ability to produce arabitol from L-arabinose, glucose, and xylose. This isolate, cultured at 28°C and 150 rpm, secreted 4.03 ± 0.00 to 7.97 ± 0.67 g/l of arabitol from 17–30 g/l of L-arabinose assimilated from a medium containing 20–80 g/l of this pentose with yields of 0.24 ± 0.00 to 0.36 ± 0.02 g/g. An optimization study demonstrated thatpH 4.0, 32°C, and a shaking frequency of 150 rpm were the optimum conditions for arabitol production by the investigated strain. Under these conditions, strain 20BM-3 produced 6.2 ± 0.17 g/l of arabitol from 17.5 g/l of arabinose after 4 days with a yield of 0.35 ± 0.01 g/g. This strain also produced arabitol from glucose, giving much lower yields, but did not produce it from xylose. The new strain can be successfully used for arabitol production from abundantly available sugars found in plant biomass

Community Level Physiological Profiles (CLPP), Characterization and Microbial Activity of Soil Amended with Dairy Sewage Sludge

The aim of the present work was to assess the influence of organic amendment applications compared to mineral fertilization on soil microbial activity and functional diversity. The field experiment was set up on a soil classified as an Eutric Cambisol developed from loess (South-East Poland). Two doses of both dairy sewage sludge (20 Mg·ha−1 and 26 Mg·ha−1) and of mineral fertilizers containing the same amount of nutrients were applied. The same soil without any amendment was used as a control. The soil under undisturbed native vegetation was also included in the study as a representative background sample. The functional diversity (catabolic potential) was assessed using such indices as Average Well Color Development (AWCD), Richness (R) and Shannon–Weaver index (H). These indices were calculated, following the community level physiological profiling (CLPP) using Biolog Eco Plates. Soil dehydrogenase and respiratory activity were also evaluated. The indices were sensitive enough to reveal changes in community level physiological profiles due to treatment effects. It was shown that dairy sewage amended soil was characterized by greater AWCD, R, H and dehydrogenase and respiratory activity as compared to control or mineral fertilized soil. Analysis of variance (ANOVA) and principal component analysis (PCA) were used to depict the differences of the soil bacterial functional diversity between the treatments

Visual assessment of the impact of agricultural management practices on soil quality

The intensification of agricultural practices to increase food and feed outputs is apressing challenge causing deterioration of soil quality and soil functions. Such achallenge demands provision of empirical evidence to provide context-sensitive guid-ance on agricultural management practices (AMPs) that may enhance soil quality.The objectives of this study are to identify the most promising AMPs (and their com-binations) applied by farmers with the most positive effects on soil quality and toevaluate the sensitivity of the soil quality indicators to the applied AMPs. The effectof selected AMPs on soil quality was assessed using a visual soil assessment tool ina total of 138 pairs of plots spread across 14 study site areas in Europe and Chinacovering representative pedo-climatic zones. The inventory and scoring of soil qual-ity were conducted together with landowners. Results show that 104 pairs show apositive effect of AMPs on soil quality. Higher effects of the AMPs were observedin lower fertile soils (i.e., Podzols and Calcisols) as opposed to higher fertile soils(i.e., Luvisols and Fluvisols). For the single use applications, the AMPs with positiveeffects were crop rotation; manuring, composting, and no-tillage; followed by organicagriculture and residue maintenance. Cluster analysis showed that the most promis-ing combinations of AMPs with the most positive effects on soil quality are composedof crop rotation, mulching, and min-till. The agreement between scientific skills andempirical knowledge in the field identified by the farmers confirm our findings andensures their applicability

Metabolic Capacity Differentiates Plenodomus lingam from P. biglobosus Subclade ‘brassicae’, the Causal Agents of Phoma Leaf Spotting and Stem Canker of Oilseed Rape (Brassica napus) in Agricultural Ecosystems

In contrast to the long-lasting taxonomic classification of Plenodomus lingam and P. biglobosus as one species, formerly termed Leptosphaeria maculans, both species form separate monophyletic groups, comprising sub-classes, differing considerably with epidemiology towards Brassicaceae plants. Considering the great differences between P. lingam and P. biglobosus, we hypothesized their metabolic capacities vary to a great extent. The experiment was done using the FF microplates (Biolog Inc., Hayward, CA, USA) containing 95 carbon sources and tetrazolium dye. The fungi P. lingam and P. biglobosus subclade ‘brassicae’ (3 isolates per group) were cultured on PDA medium for 6 weeks at 20 °C and then fungal spores were used as inoculum of microplates. The test was carried out in triplicate. We have demonstrated that substrate richness, calculated as the number of utilized substrates (measured at λ490 nm), and the number of substrates allowing effective growth of the isolates (λ750 nm), showed significant differences among tested species. The most efficient isolate of P. lingam utilized 36 carbon sources, whereas P. biglobosus utilized 60 substrates. Among them, 25–29 carbon sources for P. lingam and 34–48 substrates for P. biglobosus were efficiently used, allowing their growth. Cluster analysis based on Senath criteria divided P. biglobosus into two groups and P. lingam isolates formed one group (33% similarity). We deduce the similarities between the tested species help them coexist on the same host plant and the differences greatly contribute to their different lifestyles, with P. biglobosus being less specialized and P. lingam coevolving more strictly with the host plant

Methodological Aspects of Multiplex Terminal Restriction Fragment Length Polymorphism-Technique to Describe the Genetic Diversity of Soil Bacteria, Archaea and Fungi

The molecular fingerprinting methods used to evaluate soil microbial diversity could also be used as effective biosensors for the purposes of monitoring ecological soil status. The biodiversity of microorganisms is a relevant index of soil activity and there is a necessity to develop tools to generate reliable results for an emerging approach in the field of environmental control using microbial diversity biosensors. This work reports a method under development for determining soil microbial diversity using high efficiency Multiplex PCR-Terminal Restriction Fragment Length Polymorphism (M-T-RFLP) for the simultaneous detection of bacteria, archaea and fungi. Three different primer sets were used in the reaction and the analytical conditions were optimized. Optimal analytical conditions were achieved using 0.5 µM of primer for bacteria and 1 µM for archaea and fungi, 4 ng of soil DNA template, and HaeIII restriction enzyme. Comparative tests using the proposed analytical approach and a single analysis of each microorganism group were carried out to indicate that both genetic profiles were similar. The Jaccard similarity coefficient between single and multiplexing approach ranged from 0.773 to 0.850 for bacteria and fungi, and 0.208 to 0.905 for archaea. In conclusion, the multiplexing and pooling approaches significantly reduced the costs and time required to perform the analyses, while maintaining a proper effectiveness

The Antifungal Effect of Pyroligneous Acid on the Phytopathogenic Fungus <i>Botrytis cinerea</i>

In recent years, climate change has intensified harsh periods of rain alternating with periods of drought, leading to an increase in the presence of phytopathogenic fungi. In this study, we want to analyse the antifungal properties of pyroligneous acid against the fungal phytopathogen Botrytis cinerea. Through the inhibition test, we observed that the application of different dilutions of pyroligneous acid rarefied the growth of the fungal mycelium. Furthermore, we have seen through the metabolic profile that B. cinerea is not able to use pyroligneous acid as a resource or even grow in close contact with this resource. Moreover, we observed that the pre-incubation of the fungus in pyroligneous acid leads to a reduction in biomass production. These results give us hope for the possible use of this natural substance as a possible substance to protect plantations from pathogen attacks

The Antifungal Effect of Pyroligneous Acid on the Phytopathogenic Fungus Botrytis cinerea

In recent years, climate change has intensified harsh periods of rain alternating with periods of drought, leading to an increase in the presence of phytopathogenic fungi. In this study, we want to analyse the antifungal properties of pyroligneous acid against the fungal phytopathogen Botrytis cinerea. Through the inhibition test, we observed that the application of different dilutions of pyroligneous acid rarefied the growth of the fungal mycelium. Furthermore, we have seen through the metabolic profile that B. cinerea is not able to use pyroligneous acid as a resource or even grow in close contact with this resource. Moreover, we observed that the pre-incubation of the fungus in pyroligneous acid leads to a reduction in biomass production. These results give us hope for the possible use of this natural substance as a possible substance to protect plantations from pathogen attacks