Agglutination processes of activated sludge cultures induced by extracellular lectins

We examine the agglutinating ability of five compounds, namely, A1, A2, A3, A4 and BS1, isolated from activated sludge on selective media typical of a number of dominant microbial cultures that contribute to the formation of microbial aggregates. The morphological properties of the isolates and their lectin activity, as well as the physiological and biochemical properties of individual isolates were studied; microorganisms in their composition were identified. We assessed the capacity of the isolates under study to synthesize an exopolysaccharide matrix, as well as the sedimentation of activated sludge under the action of the native solution and culture liquid of the BS1 isolate. Based on their capacity to agglutinate, the BS1 and A2 isolates were selected for further research as producers of extracellular lectins and objects of agglutination, respectively. The biophysiochemical properties and molecular-genetic identification of the BS1 isolate allowed the degree of identity with r. Bacillus to be defined (96.19%); for the A2 isolate, 92.93% identity with p. Shigella and p. Escherichia was determined. To assess the capacity to synthesize a biofilm matrix, the BS1 and A2 isolates were cultivated on an agar nutrient solution using Congo Red dye. According to the obtained results, the isolates are capable of synthesizing an exopolysaccharide matrix, the main component of bacterial biofilms. The research results on the sedimentation of activated sludge induced by the native solution and culture liquid of BS1 showed the following. The sedimentation rate of activated sludge increased significantly at the beginning of the process upon adding a BS1 cell suspension, while the introduction of the native solution of BS1 intensified the process following 5 minutes of contact. The obtained experimental data suggest that the media containing extracellular bacterial lectins can be effectively used as a coagulant (flocculant) for the sedimentation of activated sludge.

Homeopathy: a possible weapon against multidrug-resistant bacteria to antibiotics

Background: The antimicrobial resistance is a genetic phenomenon, related to the existence of the gens restrained in microorganism that codify different biochemical mechanisms that obstruct the drugs actions. Some species present resistance widespread in all over the world, like the case of Staphylococcus aureus. This is one of the main bacteria that, in a period of time, has got multiple resistance against the antibiotics, and it’s also, an important agent causative of the nosocomiais infections. The present report evaluated the action of the different homeopathic medicines about the growth of the bacteria Staphylococcus aureus and Staphylococcus aureus MRSA (Methicillin-resistant Staphylococcus aureus) “in vitro”. Methods: Doses of 150, 250 and 350 µL of the homeopathic medicines Silicea, Hepar sulfor, Belladona, Arnica montana, Mercurio solubilis and nosode of Stafilococcus aureus, in the dynamism 6cH, 12cH e 30cH had been placed in 3mL culture liquid Mueller Hinton. It was added to this blend 10 µL of a diluted bacterial solution 1/10, where of the solution in 0,5 of the Macfarley scale in 37°C, the growth in the tubes was evaluated in Spectrophotometric of 600 nm. Results: The results demonstrated that, for the Staphilococcus aureus, we have got significant bacteria inhibition in about 70 to 90% of the growth “in vitro”, provided by the homeopathic medicines Hepar sulfor in the dynamism of 30cH, Belladona in the dynamisms of 6cH and 30cH, in the Staphilococcus aureus nosode in the dynamisms 6cH and 30cH and Silicea in the dynamism of CH6, with regard to the control with alcohol 30%. The Staphilococcus aureus MRSA presented inhibition from 40% to 20% of the bacteria growth “in vitro” related to the control with alcohol 30%, with the same medicines used before. Conclusion: We can conclude that the homeopathic medicines have an inhibitory action in the bacteria growth, including in bacteria resistance to the antibiotics. This information can suggest that a concerted action of antibiotics and homeopathic medicines, could improve the action of the antibiotics in the bacteria causative of infections in the biological tissues.

Impact of Biogenic Amines on the Growth of Green Microalgae

Background: The goal of this research project was to test various neuroactive amines in the capacity of growth stimulators/accelerators of the green microalgae Scenedesmus quadricauda and Chlorella vulgaris that have much biotechnological potential because they can be used for producing drugs, food ingredients, cosmetics, and biofuel. The issue of the ecological role of the biogenic amines in terms of interspecies communication in aqueous ecosystems was also addressed in this work. Methods: S. quadricauda strain GEHD and C. vulgaris strain ALP were cultivated in the light with constant aeration at 24oC in a minerals-containing medium. Experimental systems contained 1, 10 or 100 mM of dopamine hydrochloride, histamine hydrochloride, norepinephrine hydrochloride, or serotonin hydrochloride that were added at inoculation as freshly prepared aqueous solutions. Algal cells were counted using a light microscope , and their number in 1 mL of culture was calculated. The culture liquid and sonicated biomass of S. quadricauda and C. vulgaris were tested for the presence of endogenous amines using high-performance liquid chromatography (HPLC) with an amperometric detector. Results: The biogenic amines serotonin, norepinephrine, dopamine, and histamine significantly stimulated the growth of S. quadricauda, at concentrations of 1 and/or 10 mM but not 100 mM. Histamine was the most efficient stimulator, causing an average 65% increase in biomass accumulation at the end of the cultivation period. The effects of serotonin, dopamine and histamine on C. vulgaris were reported in our previous publication [1], but this work contains the results of our experiments with the previously untested norepinephrine that slightly stimulated the growth of C. vulgaris. HPLC analysis failed to reveal any endogenous amines in the culture liquid and biomass of both microalgae. Conclusions: Since biogenic amines stimulate the growth of the microalgae S. quadricauda and C. vulgaris but are not synthesized by them, we suggest that the algae normally respond to amines produced by other components of aqueous ecosystems, including zooplankton and fish that are known to release significant amounts of biogenic amines into the environment. The data obtained hold some promise with regard to developing a relatively economical technique of boosting algal biomass production.

RESEARCH OF AMYLOLYTIC ACTIVITY OF CULTURAL LIQUIDS IN BIOTECHNOLOGY OF SYMBIOTIC CROPS МЕDUSOMYCES GISEVII AND ORYZAMYCES INDICI

Based on the literature review found that the natural symbionts Medusomyces gisevii and Oryzamyces indici biotechnology are a valuable objects. It is urgent to find ways to impact on it in order to obtain these or other products of its life activity. At present, it is urgent to search for microorganisms producing enzymes, including amylase. One of the most promising in terms of biological objects is a natural microbial symbiont Medusomyces Gisevii (tea fungus) and Oryzamyces Indici, which, thanks to the not identical, microbiological composition and different growing conditions may have a different composition of metabolites. Studies of the amylolytic activity of the culture liquid Medusomyces Gisevii and Oryzamyces indici with different cultivation periods have been carried out. Cultivation of the fungus was carried out in the laboratory according to the classic method. The optimal concentration of sucrose for Medusomyces Gisevii and Oryzamyces Indici biomass growth was set at 5%. Sucrose concentration of 15% and above is not recommended for use due to inhibition of biomass growth with increasing concentration of carbohydrates in the culture medium. It is established that these symbionts start to show the amylolytic activity already on the 10th day of cultivation cultivation in standard nutrient medium, medium supplemented with 10 % milk and serum-based medium and stores it in the course of the experiment (30 days). Over time the amylolytic activity increases. However, the intensity of metabolism of the microorganisms, the criterion of which is the ratio of the total and exogenous amylase is most pronounced in the early stages of cultivation. It was found that the culture medium of polycultures shows high amylolytic activity. This fact allows us to consider the Medusomyces Gisevii and Oryzamyces Indici inoculum as a promising biotechnological raw material source of amylase enzyme.

Bacterial nanocellulose and softwood pulp for composite paper

Scaling biosynthesis of bacterial nanocellulose (BNC) allowed samples of composite paper with an increased proportion of BNC to be obtained. This work aims to study BNC samples and bleached soft wood kraft pulp (BSKP) composite paper with a ratio of components varying across a wide range: 10:90, 30:70, 50:50, 60:40, 70:30, 90:10. The method of paper manufacturing was chosen based on the determinations of strength and deformation properties of composite samples with the BNC:BSKP ratio of 20:80. Surface application of BNT on BSKP handsheet provided for an increase in the strength values (tear resistance – by 37%, burst index – by 17%) and deformation characteristics (tension stiffness – by 66%, fracture work – by 8%, breaking length – by 4%) compared to a reference sample. The formation of composites is confirmed in all samples. Scanning electron spectroscopy revealed that paper composites comprise interlaced micro BSKP and nano BNC fibres. As the proportion of BNC in composites elevated, densification of the structure was observed due to an increased fraction of cross-linked nanosized elements. IR spectroscopy indicated the resemblance of cellulose structure in all samples. It was found that an increase in the degree of polymerisation of composite paper is directly proportional to an increase in the BNC amount in the samples. The filtering ability of composite paper samples against microorganisms in the culture liquid of the Medusomyces gisevii Sa-12 producer was studied. It should be noted that yeast retention is achieved with 70% BNC in the paper composite. The presented properties of the new material determine prospects for its use in filtering microorganisms.

Evaluation of the secondary structure of poly-γ-glutamic acid produced by Bacillus subtilis EGP5QL12 by circular dichroism spectroscopy method

An extracellular polymer was isolated from the culture liquid of Bacillus subtilis EGP5QL12 with the yield of 5,6 g/L. On the basis of the data of thin layer chromatography, colorimetric analyses and FTIR spectroscopy, it was established that the polymer is poly-γ- glutamic acid (PGA). PGA is widely used in medicine, cosmetology and the food industry due to its ability to bind water and metal ions. To assess the biotechnological potential of the isolated polymer and predict the possibilities of its application in various fields of the national economy, it is necessary to analyze the characteristic spectral features that make it possible to establish its secondary structure. The isolated PGA preparation was analyzed by circular dichroism spectroscopy at various pH values. According to the results of this study, it was found that the polymer forms predominantly β-structures with a low proportion of irregular structures and α-helices, which gives it a high potential for creating hydrogels and composite materials.

Obtaining of new Bacillus subtilis-96 strain - a producer of proteolytic enzymes for the food industry

В результате трех этапов индуцированного мутагенеза протеолитическая активность штамма B. subtilis st 18 № 359 была увеличена более чем в 2 раза с сохранением соотношения бациллолизина и субтилизина. Концентрированный препарат, полученный из культуральной жидкости нового мутантного штамма, показал высокую эффективность при гидролизе белков молочной сыворотки. Three stages of induced mutagenesis resulted in more than 2 times increase of B. subtilis st 18 No. 359 proteolytic activity while maintaining the ratio of bacillolysin and subtilisin. The concentrated enzyme preparation obtained from the culture liquid of the new mutant strain has shown high efficiency during whey proteins hydrolysis.

ECOLIGICAL APPROACH IN IMPROVING EFFICIENCY OF INDUCTRIAL METHOD OF OBTAINING AQUACULTURE PRODUCTS

The article considers using the latest technologies with recirculation aquaculture systems (RAS), which allows growing aquaculture objects at high seeding densities all year round. However, it has a number of difficulties and, first of all, the need to purify water from metabolites. An alternative to RAS technology is an ecological approach to growing aquaculture products, which is implemented by us using the artificial eco-systems or, otherwise, agrohydroecosystems based on RAS. An experiment was carried out on the joint cultivation of a sterlet × beluga hybrid with tilapia in an aquaponic module of an integrated storey unit (IED); an increase in the mass accumulation coefficient and average daily growth rate of fish was noted. Due to the right choice of parameters that satisfy the conditions for growing all experimental objects application of IED technology allows obtaining a high increase in the mass of aquatic organisms and additional products per unit area (lettuce, strawberries). The introduction of a hydroponics block into the system reduces the amount of nitrogenous substances in the medium, while an even greater effect can be achieved by adding a microbiological preparation (culture liquid) into the system. When using an IED, raw materials and energy are consumed most efficiently, with a minimum impact on the envi-ronment.

Thermophilic Fungi with Glucosidase and Proteolytic Activities

The directed search for extremophilic producers in order to obtain hydrolytic enzymes with increased thermal stability has an unconditional practical potential for use in the food and feed industry to improve the quality of the final product. The aim of the work was to study the ability of collection strains of thermophilic fungi to show α-L-rhamnosidase, α-galactosidase, cellulase, β-mannanase, keratinase and caseinolytic activity. Methods. Micromycetes were grown under submerged conditions in test tubes at 42°C for 8–14 days. Enzymatic activities were studied in the culture liquid supernatant. p-Nitrophenyl-α-D-galactopyranoside, naringin, guar gum galactomannan and Na-carboxymethylcellulose were used as substrates to determine α-galactosidase, α-L-rhamnosidase, β-mannanase and cellulase activities, respectively. Casein and crushed defatted feathers were served as substrates for the determination of proteolytic activity. Results. The enzymatic activity of 50 strains of micromycetes belonging to 17 species was investigated. The studied group showed high activity: 94% of the strains had at least one, 34% – two, 26% – from three to five enzyme activities. The most active keratinase producers were Thielavia terrestris 1920 and 62, Rhizomucor tauricus 1909, Chrysosporium thermophilum 2050, Thermoascus thermophilus 92 and Thermoascus aurantiаcus 2052 (10–26 U/mL). The highest α-L-rhamnosidase activity was observed in T. terrestris 62 (0.35 U/mL), and carboxymethylcellulase activity −in Thermomyces lanuginosus 2046. Six strains showed α-galactosidase (0.05–0.2 U/mL) and four strains − β-mannanase (5–130 U/mL) activity. Conclusions. As a result new strains producing proteolytic and glycolytic enzymes were isolated among thermophilic micromycetes. Soil thermophilic micromycetes can be used as producers of proteolytic and glycolytic enzymes. Of particular interest are the cultures of Acremonium thermophilum 1963, Corynascus thermophilum 2050, C. sepedonium 1899 and 65068, T. thermophilus 1946, which are capable of producing complexes of proteases and glycosidases in the culture liquid. This indicates that these strains are promising for use as destructors in various technologies processing of complex raw materials.

Bioethanol Production from Miscanthus sinensis Cellulose by Bioconversion

Introduction. Cellulose-containing parts of herbs are an excellent source of alternative energy and can be used to produce biological ethanol. The present research aims at improving this fundamental and promising area of biotechnology. It introduces a new consortium of microorganisms that can saccharify while fermenting the substrate. Study objects and methods. The research featured technical cellulose obtained from Miscanthus sinensis using hydrotropic delignification and oxidation with pertrifluoroacetic acid. The ethanol content in the culture liquid was determined using an Agilent 7890B gas chromatograph with a flame ionization detector. The biocompatibility of the strains was studied by growing a direct co-culture in a dense nutrient medium. Results and discussion. The research objective was to create a new microbial consortium for the single-step production of bioethanol from Miscanthus sinensis cellulose. A set of biocompatibility experiments and cultivation conditions made it possible to select the optimal producers. The two developed microbial consortia required optimal compositions of culture media, which were determined by varying the ratio of components and measuring the yield of ethanol in the resulting culture liquid. Conclusion. The best consortium for Miscanthus sinensis cellulose consisted of Pichia stipites Y7124, Candida shehatae NCL3501, Kluyveromyces marxianus Y-4290, and Zymomonas mobilis 113 at a ratio of 1:1:1:1. The optimal parameters of bioethanol production included: temperature = 35 ± 1°C, pH = 5.2, time = 16 ± 1 h. The most efficient culture medium had the following composition (g/l): glucose – 5.0; peptone – 5.0; yeast extract – 0.4; K2HPO4 – 1.5; (NH)2 HPO4 – 1.5; MgSO4 – 0.5.