Isolation and determination of bacterial microbiota of Varroa destructor and isolation of Lysinibacillus sp. from it

Background The importance of bees for environmental health is known. Within the scope of this importance, it is of great importance to protect the health of bees and to prevent colony extinction. In this context, it is very important to develop effective methods in combating microorganisms, parasitoids, mites and organisms that cause disease or harm in bees. Both use different methods in terms of bee health. Result In this study, the possibility of the bacteria isolated from Varroa destructor mite being bioinsecticide was investigated. Accordingly, six bacteria were isolated from the mite. Isolated bacteria were analyzed according to biochemical tests, molecular analysis, optimum growth pH and phylogenetic tree drawn as Pantoea dispersa (GV1), Lysinibacillus macroides (GV3), Bacillus mycoides (GV4), Lysinibacillus fusiformis (GV5), Pseodomonas lutea (GV5), Lysinibacillus varians (GV7). Lysinibacillus sp. The entomopathogenic feature of Lysinibacillus sp. ranked it as the most important species. When the insecticidal properties of bacteria were examined, they were determined as 53, 90, 62, 95, 74 and 83% for GV1, GV3, GV4, GV5, GV6 and GV7, respectively. Conclusion Based on these results and literature review, Lysinibacillus sp. species had a high potential to be used as bioinsecticide against V. destructor mite.

COMPREHENSIVE BIOTECHNOLOGICAL APPROACH TO PROCESSING OF PEA FLOUR FOR FOOD AND FODDER PURPOSES

Investigations were carried out to optimize the growth parameters of the symbiosis of cultures of the yeast Saccharomyces cerevisiae 121 and the fungus Geotrichum candidum 977 on whey waters formed from pea flour as a secondary product in the production of protein concentrates after precipitation of proteins at the isoelectric point. The whey remaining after protein precipitation is bioconverted at optimal parameters of crop growth (pH of the medium, amount of inoculum, temperature) with the formation of microbial plant concentrate (MPC) for feed purposes. Serum cultures assimilated stachyose, glucose, maltose, arabinose, and other pentoses. The mass fraction of protein in the concentrate was 57.90-61.68 % of DS. The composition of MPC obtained from biomass is balanced in essential amino acids with a speed of 107-226 %. The fatty acid composition is represented by 97 % fatty acids and 3 % - esters, aldehydes, ketones with the properties of fragrances, photo stabilizers, odor fixers, preservatives and other compounds. The ratio of the sum of saturated and unsaturated acids is 1:3, the content of cis-isomers is 91.1 %, trans-isomers are 5.1 %, omega-6 fatty acids are 19.73 %. The quality and safety indicators indicated that it is promising for use in the diet of animals.

Biosorption of Pb (II) and Zn (II) from aqueous solution by Oceanobacillus profundus isolated from an abandoned mine

The present study investigated biosorption of Pb (II) and Zn (II) using a heavy metal tolerant bacterium Oceanobacillus profundus KBZ 3-2 isolated from a contaminated site. The effects of process parameters such as effect on bacterial growth, pH and initial lead ion concentration were studied. The results showed that the maximum removal percentage for Pb (II) was 97% at an initial concentration of 50 mg/L whereas maximum removal percentage for Zn (II) was at 54% at an initial concentration of 2 mg/L obtained at pH 6 and 30 °C. The isolated bacteria were found to sequester both Pb (II) and Zn (II) in the extracellular polymeric substance (EPS). The EPS facilitates ion exchange and metal chelation-complexation by virtue of the existence of ionizable functional groups such as carboxyl, sulfate, and phosphate present in the protein and polysaccharides. Therefore, the use of indigenous bacteria in the remediation of contaminated water is an eco-friendly way of solving anthropogenic contamination.

Nanocomposite coating based on chitosan and ZnO nanoparticles to maintain the storage quality of meatball

The effect of nanocomposite coating from chitosan incorporated with ZnO nanoparticles (ZnO NPs) at various concentrations (0, 0.05, and 0.1%) on meatball characteristics during storage was investigated. Meatball quality including microbial growth, pH, aw, and sensory attributes was evaluated after immersed into nanocomposite solution for 1 min and drained. The combination of chitosan and ZnO NPs exhibited a synergistic effect in suppressing gram-negative bacterial growth. Chitosan-ZnO NPs 0.05% could prolong the shelf life of meatball beyond 24 hrs indicated by aerobic microbes of 4.30 log CFU/g which was lower than the threshold for consumption (5 log CFU/g). Coating solution also significantly influenced the pH of meatballs up to 24 hrs of storage allowing lower sensory acceptability. Moreover, the low organoleptic score for taste and overall acceptability attributes were found as a consequence of the addition of ZnO NPs. Finally, the results of the present study suggested that chitosan-based coating containing ZnO NPs could be used as an alternative to maintaining meatball quality, particularly in microbial decay context.

Community Structure of Gastropod in Seagrass Beds of Waleo Beach Waters, North Minahasa Regency

This study aims to determine the type of Gastropod and the community structure including Species Density, Relative Density, Diversity (H’), and Dominance (C). Based on observation, there is 124 individuals included in 11 species (7 genera) from 7 families (3 orders) obtained. The highest density value is 5,87 Ind/m2 by Euplica borealis, and has 35,48% of relative density. For the diversity, an index is H’ = 1,62 obtained, which is classified as low. This shows that seagrass beds in Waleo beach waters, North Minahasa Regency, there are several species obtained with abundant numbers of individuals compared to the other species, so the diversity index obtained relatively low. As for the range of dominance index is C = 0,36 to 0,44. The lowest value is in the transect number 1 while the highest in the transect number 2. This value shows that seagrass beds in Waleo beach waters, North Minahasa Regency there are no specific species that dominate in the community. Waleo beach waters, North Minahasa Regency has a temperature of about 29,3 °C illustrating the condition of the water temperature is relatively good for Gastropods' life. The salinity is 30 ‰ obtained, which is relatively good for Gastropod growth. pH obtained about 7 which is still relatively good for gastropods life.Keywords: Gastropod, Community Structure, Waleo.AbstrakPenelitian ini bertujuan untuk menginventarisasi jenis-jenis Gastropoda serta mengetahui struktur komunitas termasuk: Kepadatan Spesies, Kepadatan Relatif, Keanekaragaman (H’), dan Dominansi (C). Berdasarkan hasil pengamatan diperoleh 124 individu yang termasuk dalam 11 spesies (7 genera) dari 7 famili (3 ordo). Nilai kepadatan tertinggi sebesar 5,87 Ind/m2 oleh spesies Euplica borealis, dan memiliki kepadatan relatif sebesar 35,48 %. Untuk indeks keanekaragaman diperoleh sebesar H’ = 1,62 yang tergolong rendah. Hal ini menunjukan bahwa daerah padang lamun perairan pantai Waleo, Kabupaten Minahasa Utara terdapat beberapa spesies yang diperoleh dengan jumlah individu yang melimpah dibandingkan jenis lainnya, sehingga indeks keanekaragaman yang diperoleh tergolong relatif rendah. Adapun untuk kisaran indeks dominansi yang diperoleh yaitu sebesar C = 0,36 sampai dengan 0,44. Nilai terrendah terdapat pada transek 1 sedangkan nilai tertinggi terdapat pada transek 2. Nilai tersebut menunjukan bahwa di padang lamun perairan Pantai Waleo, Kabupaten Minahasa Utara tidak terdapat jenis atau spesies tertentu yang mendominasi dalam komunitas tersebut. Wilayah perairan pantai Waleo, Kabupaten Minahasa Utara memiliki suhu 29,3 °C, menggambarkan bahwa kondisi suhu perairan tergolong baik untuk kehidupan Gastropoda. Salintas yang diperoleh sebesar 30 0/00, yang masih dalam kisaran baik untuk pertumbuhan Gastropoda. Derajat keasaman (pH) yang diperoleh yaitu 7 yang masih tergolong baik untuk kehidupan Gastropoda.Kata Kunci : Gastropoda, Struktur Komunitas, Waleo.

Selection of bacteria inducing calcium carbonate precipitation for self-healing concrete application

A modification of bacterial medium using calcium lactate pentahydrate was developed for calcium carbonate precipitation. A total of five strains of bacteria were cultivated on the solution medium containing nutrient broth and calcium lactate pentahydrate. In this study, the variation of 3.2 mM and 16.2 mM of calcium lactate pentahydrate was used to obtain the optimum condition for bacterial growth. The results showed that isolated strains CPB 1, CPB 3, and CPB 5 with medium containing nutrient broth and 3.2 mM calcium lactate pentahydrate gave the optimum growth, pH and Eh, thus being favourable for the process of calcium carbonate precipitation. Hence, this will be useful for self-healing concrete.

Optimization of manganese bioleaching activity and molecular characterization of indigenous heterotrophic bacteria isolated from the sulfuric area

Prasidya DA, Wilopo W, Warmada IW, Retnaningrum E. 2019. Optimization of manganese bioleaching activity and molecular characterization of indigenous heterotrophic bacteria isolated from the sulfuric area. Biodiversitas 20: 1904-1909. The present research evaluated the manganese bioleaching potency of a heterotrophic bacteria KB3B1. This bacterial strain has been isolated from sulfuric area located at Ungaran, Middle of Java, Indonesia using modified 9K medium by adding of several organic nutrients. The manganese bioleaching activities of the strain was analysed by applying of varying glycine concentrations (0, 5, 10, 15 mg mL-1) with pyrolusite pulp densities of 0.02 g cm-3 on a rotary shaker at 180 rpm for 18 days incubation. Several parameters, including the growth of bacteria, pH values, the concentration of soluble manganese and cyanide, were investigated at the interval of 3 days. Molecular characteristics of the strain were further analyzed based on 16S rDNA gene sequences. After 15 days, the maximum yield of manganese 16.6% was achieved under the addition of 10 mg mL-1 glycine. This maximum extract obtained was followed by the maximum bacterial growth, pH, and cyanide product of the strain. Phylogenetic analysis showed that the strain was closely related with Bacillus niacini EP89. Besides, the average frequencies of guanine and cytosine (G+C) of the strain was in same range as that of the reference bacteria in the GenBank and Bergey's Manual Systematics of Bacteria.