• The Plant Pathology Journal
• /
• v.38 no.5
• /
• pp.449-460
• /
• 2022

This study was performed to reveal phenotypic characters and identity of symbiont bacteria of Nasutitermes as well as investigate their potential as antagonist of plant pathogenic fungi. Isolation of the symbiont bacteria was carried out from inside the heads and the bodies of soldier and worker termite which were collected from 3 locations of nests. Identification was performed using phenotypic test and sequence of 16S ribosomal DNA (16S rDNA). Antagonistic capability was investigated in the laboratory against 3 phytopathogenic fungi i.e., Phytophthora capsici, Ganoderma boninense, and Rigidoporus microporus. Totally, 39 bacterial isolates were obtained from inside the heads and the bodies of Nasutitermes. All the isolates showed capability to inhibit growth of P. capsici, however, 34 isolates showed capability to inhibit growth of G. boninense and 32 isolates showed capability to inhibit growth of R. microporus. Two bacterial strains (IK3.1P and 1B1.2P) which showed the highest percentage of inhibition were further identified based on their sequence of 16S rDNA. The result showed that 1K3.1P strain was placed in the group of type strain and reference strains of Lysinibacillus fusiformis meanwhile 1B1.2P strain was grouped within type strain and reference strains Paenibacillus alvei. The result of this study supply valuable information on the role of symbiont bacteria of Nasutitermes, which may support the development of the control method of the three above-mentioned phytopathogenic fungi.

• KSBB Journal
• /
• v.14 no.2
• /
• pp.198-204
• /
• 1999

Asymbiotic bacterium with highly effective toxins was isolated from entomopathogenic nematode Steinernema glaseri which has been widely used against various soil-inhabiting pests. The symbiont of S. glaseri was identified as Xenorhabdus nematophilus sp. by using several biochemical and physiological tests. When this strain was released into the hemolymph of insect larva, it produced highly toxic substances and killed the larva within 2 days. Two colony forms that differed n some biochemical characteristics were observed when cultures in vitro. Phase l colonies were mucid and difficult to be dispersed in liquid. Phase II was not mucoid and was easily dispersed in liquid. It did not adsorb neutral red or bromothymol blue. Rod-shaped cell size was highly variable between two phases, ranging 2-10 ${\mu}{\textrm}{m}$. It was also found that only infective-stage nematodes can carry only primary-phase Xenorhabdus in their intestine.

• Microbiology and Biotechnology Letters
• /
• v.20 no.1
• /
• pp.96-101
• /
• 1992

Two strains of polyvinyl alcohol (PVA) utilizing bacteria were isolated from the waste water and soil. These strains, G5Y and PW, were able to utilize PVA symbiotically as a carbon source, but could not utilize PVA separately. In the mixed culture of these strains, 0.5 percent of PVA was almost completely degraded in 3 days. Effect of degree of PVA polymerization on the its utilization was examined, and there was no remarkable difference among three kind of PVA (PVA 500, 1500, a d 2000). These bacteria were able to utilize PV,4 in the desizing waste water of factory as well as enrichment PVA medium. These strains, C5Y and PW, were identified as Pseudomonas cepucia and Pseudomonus pseudomallei, respectively, based on morpholofical and biological characteristics.

• Journal of Marine Bioscience and Biotechnology
• /
• v.5 no.4
• /
• pp.15-25
• /
• 2011

Marine sponges are a rich source of highly diversified bioactive compounds. These medicinally valuable molecules represent extreme physiological and ecological functions in sponges, more presumably involving in the resistance to the feeding by other marine organisms like fish and fouling by barnacles, bacteria, fungi, etc. This feature of attaining resistance made sponges as successful poriferans that possess an impressive array of biological properties ranging from antimicrobial to anticancerous activities. The diversified bioactive principle of sponges might be due to their spacio-temporal distribution and although, the gateway for exploiting the sponges for isolating these distinct, potential molecules is open, suitable technical and methodological approaches are yet to be implemented in order to bring the sponges as successful pharmaceutical leads in the field of marine biotechnology. Despite of the identified difficulties of marine sponge research from past few decades, one should concentrate not only on the basic and applied technical/methodological considerations, but also on the novel strategies like in vitro sponge cell, fragment and whole sponge culture; sponge symbiont cell culture; in situ and ex situ sponge cultivation; and sponge bioreactors and metagenomic approaches, for the successful exploitation of marine sponges towards the novelty in sponge biotechnology. The present review narrates the pros and cons of the nowadays-marine sponge research by focusing on the suggestive ecobiotechnological approaches, based on the latest studies for feasible ecological exploitation and biotechnological application of sponges from the sea.

• Parasites, Hosts and Diseases
• /
• v.59 no.5
• /
• pp.489-496
• /
• 2021

Ticks can transmit pathogenic bacteria, protozoa, and viruses to humans and animals. In this study, we investigated the microbiomes of Haemaphysalis longicornis according to sex and life stages. The Shannon index was significantly higher for nymphs than adult ticks. Principal coordinates analysis showed that the microbiome composition of female adult and male adult ticks were different. Notably, Coxiella-like bacterium (AB001519), known as a tick symbiont, was found in all nymphs and female adult ticks, but only one out of 4 male adult ticks had Coxiella-like bacterium (AB001519). In addition, Rickettsia rickettsii, Coxiella burnetii, and Anaplasma bovis were detected in this study.

• Applied Biological Chemistry
• /
• v.35 no.1
• /
• pp.30-35
• /
• 1992

Two strains J2W and J2Y which were isolated from soil can utilize polyvinyl alcohol(PVA) as a sole carbon source. PVA was utilized symbiotically by the mixed culture of these two strains which could not utilize PVA in each respective pure culture. Effect of degree of PVA polymerization on the its utilization was examed, and there was remarkable difference among three kind of PVA(PVA 500, 1500 and 2000). The reconstruction of there two strains was carried out with other symbionts Pseudomonas sp. PW and Pseudomonas sp. G5Y which were able to utilize PVA. PVA utilization occured in each remixed culture of J2Y strain with Pseudomonas sp. PW J2W strain with Pseudomonas sp. G5Y, respectively. Identification of bacteria was based on morphological and biological chatacteristics, J2W and J2Y strain were similar to a strain of Pseudomonas pseudimallei and Xanthomonas campestris, respectively.

• Korean Journal of Organic Agriculture
• /
• v.30 no.1
• /
• pp.103-118
• /
• 2022

Photorhabdus is a bacterial symbiont of entomopathogenic nematodes of the genus Heterorhabditis in the family Heterorhabditidae. Photorhabdus is known to have nematicidal activity in addition to insecticidal activity. P. temperata isolated from Korean indigenous H. megidis Gwangju strain also produced high control efficacy against root-knot nematode Meloidogyne incognita and root-lesion nematode Pratylenchus penetrans. P. temperata has drawn interest as a potential bionematicide for the control of root-knot nematodes thereby. For the registration as an organic agricultural material, the toxicity of P. temperata was assessed by the acute toxicity test in carp (Cyprinus carpio) and acute oral and dermal toxicity tests in Sprague-Dawley rat (Rattus norvegicus) in compliance with the guidelines of the Rural Development Administration (RDA). In the acute toxicity test in fish, neither lethality nor abnormal responses of carp were observed. Body length and weight of carp and changes in DO concentrations and pH values were not significantly different between the treated group and the untreated control. In the acute oral and dermal toxicity tests, clinical signs, abnormal behavior, mortality, and pathological findings were not observed in all the experimental rats. The weight increment of all rats was normal. Acute toxicity results of P. temperata in fish and rats belonged to categories III, IV, and IV of RDA, respectively. Toxicity results of the present study indicated that P. temperata could be a safe and promising bionematicide against root-knot nematodes and root lesion nematode.

• Korean Journal of Soil Science and Fertilizer
• /
• v.21 no.2
• /
• pp.141-148
• /
• 1988

Though the cultivation history of soybean in Korea is relatively long, taxonomical study on symbiont nodule bacteria, Rhizobium japonicum is not carried out yet systematically. This work was for the taxonomical study on Korean native R. japonicum by recognizing isolates seroimmunologically as well as for the elucidation of its affinity with host soybean variety. Twenty seven isolates from 13 soybean cultivars cultivated at Seoul National University's experiment field and 6 strains of R. japonicum preserved in our laboratory have been tested. Tube agglutination test, agglutinin adsorption test, and gel immune diffusion test were used. The results obtained are as follows: 1. Twenty five isolates and strains of R. japonicum among 33 were classified into 4 serogroups and identified as indivisual serotype. 2. Two isolates isolated from Hill and Milyang cultivars, 2 isolates from Bangsa and Jangbaek, and 4 isolates from Paldal, Sae-al, and Jangbaek were identified as the same serotype respectively. 3. Seroimmunological tests may be adapted for the elucidation of the affinities between the strains and soybean cultivars as well as strain recognition and systematic classification of Korean native R. japonicum.

• Parasites, Hosts and Diseases
• /
• v.61 no.1
• /
• pp.60-71
• /
• 2023

Cockroaches can cause allergic sensitization in humans via contact with their feces or frass. Antibiotics can affect concentration of major allergen and total bacteria production in German cockroaches (Blattella germanica). This study examined the ability of antibiotic-treated German cockroaches to induce allergic airway inflammation and the effect of antibiotics on their lipopolysaccharide and Bla g1, 2, and 5 expression levels. Specifically, we measured the ability of German cockroach extract (with or without prior antibiotic exposure) to induce allergic inflammation in human bronchial epithelial cells and a mouse model of asthma. Bacterial 16S rRNA and lipopolysaccharide levels were lower in ampicillin-treated cockroaches than in the control group. The Bla g1, Bla g2, and Bla g5 expression in ampicillin-treated cockroaches decreased at both the protein and RNA levels. In human bronchial epithelial cell lines BEAS-2B exposed to the ampicillin-treated extract, expression levels of interleukin-6 and interleukin-8 were lower than that in the control group. The total cell count and eosinophil count in bronchoalveolar lavage fluid was also lower in mice exposed to the ampicillin-treated extract than in those exposed to normal cockroach extract. Mouse lung histopathology showed reduced immune cell infiltration and mucus production in the ampicillin group. Our results showed that ampicillin treatment reduced the symbiont bacterial population and major allergen levels in German cockroaches, leading to reduced airway inflammation in mice. These results can facilitate the preparation of protein extracts for immunotherapy or diagnostics applications.