Volatile Organic Compounds and Physiological Parameters as Markers of Potato (Solanum tuberosum L.) Infection with Phytopathogens.

The feasibility of early disease detection in potato seeds storage monitoring of volatile organic compounds (VOCs) and plant physiological markers was evaluated using 10 fungal and bacterial pathogens of potato in laboratory-scale experiments. Data analysis of HS-SPME-GC-MS revealed 130 compounds released from infected potatoes, including sesquiterpenes, dimethyl disulfide, 1,2,4-trimethylbenzene, 2,6,11-trimethyldodecane, benzothiazole, 3-octanol, and 2-butanol, which may have been associated with the activity of Fusarium sambucinum, Alternaria tenuissima and Pectobacterium carotovorum. In turn, acetic acid was detected in all infected samples. The criteria of selection for volatiles for possible use as incipient disease indicators were discussed in terms of potato physiology. The established physiological markers proved to demonstrate a negative effect of phytopathogens infecting seed potatoes not only on the kinetics of stem and root growth and the development of the entire root system, but also on gas exchange, chlorophyll content in leaves, and yield. The negative effect of phytopathogens on plant growth was dependent on the time of planting after infection. The research also showed different usefulness of VOCs and physiological markers as the indicators of the toxic effect of inoculated phytopathogens at different stages of plant development and their individual organs.

Dark fermentative hydrogen production from hydrolyzed sugar beet pulp improved by nitrogen and phosphorus supplementation.

The effect of nitrogen and phosphorous addition on hydrogen production from hydrolyzed Sugar beet pulp (SBP) was investigated using (NH4)3PO4, NH4Cl and K3PO4 as the supplements. In batch tests, the maximal hydrogen production of 279 dm3/kgVS was observed for K3PO4, which was added to SBP in a dose of 1 g/dm3. In semi-continuous experiments, the greatest hydrogen production of 36 dm3/kgVS was reported for the same supplement, and this value was twice higher than that of the control run. The analysis of microbiota revealed that the majority of bacteria was affiliated to the orders Clostridiales, Lactobacillales and Coriobacteriales. Moreover, a noticeable methane production was associated with the activity of Methanosphaera sp., which could grow in a low pH environment of dark fermentation.

Dark fermentative hydrogen production from hydrolyzed sugar beet pulp improved by iron addition.

This study evaluated the impact of three different iron compounds (Fe2O3, FeSO4, FeCl3) on hydrogen production via mesophilic dark fermentation (DF) of hydrolyzed sugar beet pulp (SBP). In batch tests, the maximum hydrogen yield of over 200 dm3H2/kgVS was achieved with the addition of 0.1 gFe2O3/dm3, which was twice greater than the control. In semi-continuous experiments, the highest hydrogen production of 52.11 dm3H2/kgVS combined with 19.4 dm3CH4/kgVS methane yield was obtained at a dose of 1 gFe2O3/dm3. Acetic, lactic and caproic acids were the main metabolic products of DF. Microbiological studies showed some balance between hydrogen producing microorganisms from the order Clostridiales and lactic acid producers (LAB) affiliated with the orders Lactobacillales and Coriobacteriales. Moreover, the presence of methanogens affiliated to the genera Methanobrevibacter and Methanosphaera was also documented. An interesting finding was the appearance of rare bacteria from the genus Caproiciproducens, which was responsible for increased caproic acid production.

The use of sugar beet pulp stillage for co-digestion with sewage sludge and poultry manure.

The anaerobic mesophilic co-digestion of sugar beet pulp stillage with poultry manure and municipal sewage sludge was investigated in this study. The sugar beet pulp stillage (SBPS) mono-digestion failed owing to an accumulation of volatile fatty acids, leading to a pH value lower than 5.5. A 20% addition of poultry manure to stillage allowed for stable digestion performance despite high volatile fatty acid (total volatile fatty acids) concentrations of 5500-8500 g m-3 with propionic acid being the predominant one and constituting 72%-76% total volatile fatty acids. For this mixture, the maximum methane production of 418 dm3 kgVSfed-1 was achieved when the reactor was operated at a solids retention time of 20 days and an organic loading rate of 4.25 kgVS m-3 d-1. The co-digestion of stillage with 60% municipal sewage sludge gave the average methane yield of around 357 dm3 kgVSfed-1 for all operational conditions applied, however, the methane percentage of biogas (up to 70%) was far greater than the corresponding values obtained for sugar beet pulp stillage-poultry manure co-digestion. Neither ammonia nor volatile fatty acids destabilised the biogas production, and the volatile fatty acid profile showed the dominance of acetic acid (72%-82% total volatile fatty acids) followed by propionic and butyric acids.

Simultaneous Saccharification and Fermentation of Sugar Beet Pulp with Mixed Bacterial Cultures for Lactic Acid and Propylene Glycol Production.

Research into fermentative production of lactic acid from agricultural by-products has recently concentrated on the direct conversion of biomass, whereby pure sugars are replaced with inexpensive feedstock in the process of lactic acid production. In our studies, for the first time, the source of carbon used is sugar beet pulp, generated as a by-product of industrial sugar production. In this paper, we focus on the simultaneous saccharification of lignocellulosic biomass and fermentation of lactic acid, using mixed cultures with complementary assimilation profiles. Lactic acid is one of the primary platform chemicals, and can be used to synthesize a wide variety of useful products, including green propylene glycol. A series of controlled batch fermentations was conducted under various conditions, including pretreatment with enzymatic hydrolysis. Inoculation was performed in two sequential stages, to avoid carbon catabolite repression. Biologically-synthesized lactic acid was catalytically reduced to propylene glycol over 5% Ru/C. The highest lactic acid yield was obtained with mixed cultures. The yield of propylene glycol from the biological lactic acid was similar to that obtained with a water solution of pure lactic acid. Our results show that simultaneous saccharification and fermentation enables generation of lactic acid, suitable for further chemical transformations, from agricultural residues.

The use of Yucca schidigera and microbial preparation for poultry manure deodorization and hygienization.

The aim of this study was to determine the effectiveness of microbial preparation and Yucca schidigera in the removal of odorous volatile compounds from poultry manure as well as to evaluate antimicrobial properties of these amendments. It was demonstrated that the combined treatment of poultry manure (PM) with the microbial preparation and Y. schidigera extract can reduce the concentration of odorants by 58%-73%, depending on the tested compound. When Y. schidigera extract and the microbial preparation were applied at a time interval of 48 h, the deodorization efficiency was improved by 6-24%. Furthermore, Y. schidigera extract has antimicrobial properties, which affect poultry manure hygienization. It was found that when the microbial preparation was enriched with Lactobacillus plantarum, it became insensitive to the antimicrobial properties of Y. schidigera.

Co-digestion of sewage sludge and dewatered residues from enzymatic hydrolysis of sugar beet pulp.

UNLABELLED: Sugar beet pulp residues (SBPR) from hydrolysis and dewatering of beet pulp were co-digested with municipal sewage sludge (MSS). The highest biogas yields of nearly 512 dm(3)/kg VSfed (volatile solids fed) were achieved for SBPR, treated both as the monosubstrate and as a mixture with MSS (1 : 1 by weight). Simultaneously, the highest methane production of 348 dm(3) CH4/kg VSfed was determined when the sewage sludge was co-digested with 35% SBPR. The analysis of digestate showed that neither ammonia nor volatile fatty acids destabilized the biogas production. IMPLICATIONS: Processing of sugar beet pulp into bioethanol via enzymatic hydrolysis and microbial fermentation has become increasingly attractive. However, in this process, only the liquid fraction derived from hydrolysis is subjected into alcoholic fermentation, whereas the remaining solid fraction needs to be utilized. This study demonstrated that sugar beet pulp residues after bioethanol production can successfully be co-digested with sewage sludge to increase biogas productivity of anaerobic digesters located at wastewater treatment plants.

Removal of odorous compounds from poultry manure by microorganisms on perlite--bentonite carrier.

Laboratory-scale experiments were conducted using poultry manure (PM) from a laying hen farm. Six strains of bacteria and one strain of yeast, selected on the base of the previous study, were investigated to evaluate their activity in the removal of odorous compounds from poultry manure: pure cultures of Bacillus subtilis subsp. spizizenii LOCK 0272, Bacillus megaterium LOCK 0963, Pseudomonas sp. LOCK 0961, Psychrobacter faecalis LOCK 0965, Leuconostoc mesenteroides LOCK 0964, Streptomyces violaceoruber LOCK 0967, and Candida inconspicua LOCK 0272 were suspended in water solution and applied for PM deodorization. The most active strains in the removal of volatile odorous compounds (ammonia, hydrogen sulfide, dimethylamine, trimethylamine, isobutyric acid) belonged to B. subtilis subsp. spizizenii, L. mesenteroides, C. inconspicua, and P. faecalis. In the next series of experiments, a mixed culture of all tested strains was immobilized on a mineral carrier being a mixture of perlite and bentonite (20:80 by weight). That mixed culture applied for PM deodorization was particularly active against ammonia and hydrogen sulfide, which were removed from the exhaust gas by 20.8% and 17.5%, respectively. The experiments also showed that during deodorization the microorganisms could reduce the concentrations of proteins and amino acids in PM. In particular, the mixed culture was active against cysteine and methionine, which were removed from PM by around 45% within 24 h of deodorization.