Some Basidiomycota were chosen for studies of key ligninases synthesis (25°C, 30 days) in modified medium (shaken or not cultures) with added wheat straw. Liquid Czapek medium with straw yielded a higher amount of laccase than peroxidase, ground straw induced enzyme worse than chopped straw. With peroxidase the reverse dependencies were observed. Laccase of Lentinus edodes synthesized two enzyme isoforms (ca 30 and 16 kDa). In T. versicolor culture active laccase protein with highest molecular mass ca 65 kDa was found. P. sajor-caju yielded three different peroxidase isoforms. Ligninase biosynthesis depended on strain, straw fragmentation extent, culture method and growth medium.
Plant Growth-Promoting Bacteria (PGPB) are a promising alternative to conventional fertilization. One of the most interesting PGPB strains, among the spore-forming bacteria of the phylum Firmicutes, is Bacillus pumilus. It is a bacterial species that inhabits a wide range of environments and shows resistance to abiotic stresses. So far, several PGPB strains of B. pumilus have been described, including B. pumilus LZP02, B. pumilus JPVS11, B. pumilus TUAT-1, B. pumilus TRS-3, and B. pumilus EU927414. These strains have been shown to produce a wide range of phytohormones and other plant growth-promoting substances. Therefore, they can affect various plant properties, including biometric traits, substance content (amino acids, proteins, fatty acids), and oxidative enzymes. Importantly, based on a study with B. pumilus WP8, it can be concluded that this bacterial species stimulates plant growth when the native microbiota of the inoculated soil is altered. However, there is still a lack of research with deeper insights into the structure of the native microbial community (after B. pumilus application), which would provide a better understanding of the functioning of this bacterial species in the soil and thus increase its effectiveness in promoting plant growth.
Cellulolytic enzymes produced by spore-forming bacteria seem to be a potential solution to the degradation of lignocellulosic waste. In this study, several dozen bacterial spore-forming strains were isolated from soil and one of them was selected for further studies. The studied bacterial strain was identified to genus Bacillus (strain 8E1A) by 16S rRNA gene sequencing. Bacillus sp. 8E1A showed an activity of carboxymethyl cellulase (CMCase) with visualization with Congo Red-25 mm (size of clear zone). To study CMCase, filter paper hydrolase (FPase), and microcrystalline cellulose Avicel hydrolase (Avicelase) production, three different cellulose sources were used for bacterial strain cultivation: carboxymethyl cellulose (CMC), filter paper (FP), and microcrystalline cellulose Avicel. The highest CMCase (0.617 U mL−1), FPase (0.903 U mL−1), and Avicelase (0.645 U mL−1) production of Bacillus sp. 8E1A was noted for using CMC (after 216 h of incubation), Avicel cellulose (after 144 h of incubation), and CMC (after 144 h of incubation), respectively. Subsequently, the cellulases’ activity was measured at various temperatures and pH values. The optimal temperature for CMCase (0.535 U mL−1) and Avicelase (0.666 U mL−1) activity was 70 °C. However, the highest FPase (0.868 U mL−1) activity was recorded at 60 °C. The highest CMCase and Avicelase activity was recorded at pH 7.0 (0.520 and 0.507 U mL−1, respectively), and the optimum activity of FPase was noted at pH 6.0 (0.895 U mL−1). These results indicate that the cellulases produced by the Bacillus sp. 8E1A may conceivably be used for lignocellulosic waste degradation in industrial conditions.
The ecology of cellulolytic bacteria in bulk soil is still relatively unknown. There is still only a handful of papers on the abundance and diversity of this group of bacteria. Our study aimed to determine the impact of various crop management systems and farmyard manure (FYM) fertilization on the abundance of cellulolytic and potentially cellulolytic spore-forming bacteria (SCB). The study site was a nearly 100-year-old fertilization experiment, one of the oldest still active field trials in Europe. The highest contents of total carbon (TC) and total nitrogen (TN) were recorded in both five-year rotations. The abundances of SCB and potential SCB were evaluated using classical microbiological methods, the most probable number (MPN), and 16S rRNA Illumina MiSeq sequencing. The highest MPN of SCB was recorded in soil with arbitrary rotation without legumes (ARP) fertilized with FYM (382 colony-forming units (CFU) mL−1). As a result of the bioinformatic analysis, the highest values of the Shannon–Wiener index and the largest number of operational taxonomic units (OTUs) were found in ARP-FYM, while the lowest in ARP treatment without FYM fertilization. In all treatments, those dominant at the order level were: Brevibacillales (13.1–43.4%), Paenibacillales (5.3–36.9%), Bacillales (4.0–0.9%). Brevibacillaceae (13.1–43.4%), Paenibacillaceae (8.2–36.9%), and Clostridiaceae (5.4–11.9%) dominated at the family level in all tested samples. Aneurinibacillaceae and Hungateiclostridiaceae families increased their overall share in FYM fertilization treatments. The results of our research show that the impact of crop management types on SCB was negligible while the actual factor shaping SCB community was the use of FYM fertilization.
The main idea of a circular economy (CE) is to separate economic growth from resource consumption and environmental impacts. The characteristic approach of a CE assumes the minimisation of the amount of waste generated at the design level and, as a standard, includes innovations throughout the value chain. From an agricultural point of view, agricultural biogas plants are particularly important because they enable the management of all waste biomass and its conversion into useful energy and agricultural fertiliser. This paper presents methods for assessing the economic effectiveness of an investment in an agricultural biogas plant. The research goal was to develop a financial model. The authors of this study used available examples of the profitability of commercial ventures. We considered the investment aspects of agricultural biogas plants. Exemplary solutions are discussed, allowing the reader to become acquainted with various methods and proposals for thus far estimated investments. It may seem chaotic, but this is how the biogas market is characterised in the context of the implementation of biogas projects. Guidance is given regarding how to understand investing in this sensitive private farming sector. It is admirable that the renewable energy market has been systematised, and we hypothesise that it is necessary to develop an investment model in Polish conditions.
Effective microorganisms (EM) technology was used to find the optimal method of water restoration in the designated experimental area. The study aimed to evaluate the impact of EM biopreparation on selected physicochemical and microbiological properties using ISO methods. A week after the application of biopreparations, a slight decrease in the nitrates content (0.375–0.531 mg L−1) and a significant decrease in the content of phosphorus compounds (0.130–0.304 mg L−1) compared to the control date were observed. Moreover, on the second date, the decrease in most values of microbiological properties was noted. Two weeks after the application, in most cases, the values of water quality properties were shaped close to values obtained in the control date (before EM application). The EM effect was rather short-term, but optimization of application properties may prolong the effect and thus, include the EM technology among the best eco-friendly technologies used for freshwater ecosystem restoration.
Recently, an increasing interest in such fertilizers and fertilization methods which not only directly supply nutrients to plants, but also stimulate soil bioactivity is noted. Their effect on both soil microbiota and forage plants has not been fully recognized. The aim of the study was to investigate the combined effect of forage plant mixture type and mineral fertilizers (NPK) with biostimulants based on a marine algae extracts on the botanical composition, yield, the structure of selected taxonomic and trophic groups of soil microorganisms, and the soil enzymatic activity. During the years 2018–2019 a field experiment established in split-plot design with two different forage plant mixtures, as a first factor, and different fertilization basing on mineral fertilizers amended with biostimulants, as a second factor was conducted. Two types of forage mixtures of sown species were used: grass mixture (GM) and legume-grass mixture (LGM). Every year the following biostimulants were applied: N-14, PinKstart, Physiostart, Physioactive and they were compared with standard NPK fertilisation and no fertilisation as a control. The reaction of forage plant mixtures on applied fertilisation was different. The intensive development of grass species, mainly Lolium perenne, at the expense of Trifolium repens share in LGM was observed. In GM sward dominated Dactylis glomerata. A beneficial effects of biostimulants’ application on the biomass yields of both grass mixtures was observed. The systematic soil acidification and a decrease of soil enzymatic activity in result of applied fertilization, except NPK + Physioactive treatment (calcium fertilizer containing 76% calcium carbonate), was noted. Soil reaction to applied fertilisation was dependent on the botanical composition of the sward. The counts of microorganisms in the soil under LGM were almost two times higher than in the soil under GM. The most effective, in reducing the negative effect of nitrogen mineral fertilization on the pH of soil, was fertilization with NPK + Physioactiv.
The bioconversion of cellulose to soluble sugars by diazotrophic bacteria is a very important for the environment, such as for the global stabilization and a sustainable human society. Two nitrogen-fixing microorganisms hydrolyzing cellulose were isolated from agricultural soil and identified as Paenibacillus polymyxa [the laboratory names EG2 and EG14] based on 16Sr RNA sequence. The genome of these bacteria was found to carry nif genes coding the individual components of the nitrogenase complex. Their nitrogen fixing ability was confirmed by studying nitrogenase activity in cultures of the studied bacteria in N-free medium supplemented with carboxymethylcellulose (CMC). The nitrogenase activity of P. polymyxa EG 2 was 2.9 nM C 2 H 4 •ml -1 •h -1 whereas P. polymyxa EG 14 0.4nM C 2 H 4 •ml -1 •h -1 . The isolates in medium with filter paper synthesize following cellulolytic enzymes: carboxymethylcellulase (CMCase), FPase and Avicellase. Of the cellulolytic enzymes in the culture supernatants of the bacteria the most abundant was CMCase (P. polymyxa EG 2 103.4 mU, EG 14:96.1 mU) with far lower amounts of enzymes hydrolyzing crystalline Avicel cellulose or filter paper. In spite of these observations the better isolate in terms of synthesis of cellulases is P. polymyxa EG 14. Zymograms reflecting the main cellulase activities of the studied bacteria do not significantly differ from each other and present at least three major enzymatic activities with high molecular masses: one of about 200 kDa, another of about 220 kDa and a strong band of activity with mass of about 130 KDa. Observations of the bacterial cultures in medium with filter paper revealed the colonization of the substrate by single cells or aggregates of bacterial cells surrounded by slime. Scanning and transmission microscopy of the isolates revealed the presence of spherical structures resembling cellulosomes on the surface of the bacteria being characteristic for anaerobic bacteria of the genus Clostridium. Citation: Górska EB, Jankiewicz U, Dobrzyński J, Russel S, Pietkiewicz S, et al. (2015) The aim of our studies was to determine the activity of the cellulolytic enzymes produced by two diazotrophic strains of the bacterium P. polymyxa isolated from soil and to visualize cellulosomes on the surface of the studied bacteria as well as the colonization of cellulose by the bacterial cells using microscopy techniques. Journal of Bior emediation & Biodegradation Materials and MethodsThe studies involved two strains of facultatively anaerobic sporeforming bacteria isolated from agriculturally used land. Based on the morphology of cells in 18-20 hour cultures of the bacteria in broth and of colonies on nutrient agar incubated at 28°C as well as on biochemical traits identified using Biomerieux API 50 CHB test the isolates were preliminarily classified to the genus Paenibacillus. To identify the isolates to species the sequence of their 16S rRNA was determined. To amplify the 16S RNA gene universal starters 27 F and 1401R were used. The matrix f...
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