著者

Gen Enomoto Ayako Kamiya Yukiko Okuda Rei Narikawa Masahiko Ikeuchi

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2020.01.007, (Released:2020-03-30)

参考文献数

43

被引用文献数

6

---

Second messenger molecules are crucial components of environmental signaling systems to integrate multiple inputs and elicit physiological responses. Among various kinds of second messengers, cyclic nucleotides cAMP and cyclic di-GMP (c-di-GMP) play pivotal roles in bacterial environmental responses. However, how these signaling systems are interconnected for a concerted regulation of cellular physiology remains elusive. In a thermophilic cyanobacterium Thermosynechococcus vulcanus strain RKN, incident light color is sensed by cyanobacteriochrome photoreceptors to transduce the light information to the levels of c-di-GMP, which induces cellular aggregation probably via cellulose synthase activation. Herein, we identified that Tlr0485, which is composed of a cGMP-specific phosphodiesterases, adenylate cyclases, and FhlA (GAF) domain and an HD-GYP domain, is a cAMP-activated c-di-GMP phosphodiesterase. We also show biochemical evidence that the two class-III nucleotide cyclases, Cya1 and Cya2, are both adenylate cyclases to produce cAMP in T. vulcanus. The prevalence of cAMP-activated c-di-GMP phosphodiesterase genes in cyanobacterial genomes suggests that the direct crosstalk between cAMP and c-di-GMP signaling systems may be crucial for cyanobacterial environmental responses.

著者

Toshirou Nagai Shigeru Oita

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.50, no.2, pp.115-118, 2004 (Released:2006-03-24)

参考文献数

12

被引用文献数

4 4

著者

Tomonori Kashimoto Keita Miyake Mayuko Sato Kaisei Maeda Chikahiro Matsumoto Masahiko Ikeuchi Kiminori Toyooka Satoru Watanabe Yu Kanesaki Rei Narikawa

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2019.11.008, (Released:2020-03-07)

参考文献数

43

被引用文献数

5

---

The cyanobacterium Acaryochloris marina MBIC 11017 (A. marina 11017) possesses chlorophyll d (Chl. d) peaking at 698 nm as photosystem reaction center pigments, instead of chlorophyll a (Chl. a) peaking at 665 nm. About 95% of the total chlorophylls is Chl. d in A. marina 11017. In addition, A. marina 11017 possesses phycobilisome (PBS) supercomplex to harvest orange light and to transfer the absorbing energy to the photosystems. In this context, A. marina 11017 utilizes both far-red and orange light as the photosynthetic energy source. In the present study, we incubated A. marina 11017 cells under monochromatic orange and far-red light conditions and performed transcriptional and morphological studies by RNA-seq analysis and electron microscopy. Cellular absorption spectra, transcriptomic profiles, and microscopic observations demonstrated that PBS was highly accumulated under an orange light condition relative to a far-red light condition. Notably, transcription of one cpcBA operon encoding the phycobiliprotein of the phycocyanin was up-regulated under the orange light condition, but another operon was constitutively expressed under both conditions, indicating functional diversification of these two operons for light harvesting. Taking the other observations into consideration, we could illustrate the photoacclimation processes of A. marina 11017 in response to orange and far-red light conditions in detail.

著者

Kazuki Ohta Tenma Shimizu Taku Oshima Norikazu Ichihashi

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2022.10.003, (Released:2022-11-15)

参考文献数

29

---

Various bacteria can change to a spherical cell-wall-deficient state, called L-from, in the presence of antibiotics that inhibit cell wall synthesis. L-forms are classified into two types: unstable and stable L-forms. Unstable L-forms revert to a normal walled state in the absence of antibiotics, while stable L-forms remain in their wall-deficient state. The conversion from unstable to stable L-forms has been often observed during long-term cultivation. However, the genetic cause for this conversion is not yet fully understood. Here, we obtained stable Bacillus subtilis L-form strains from unstable L-form strains via three independent long-term culturing experiments. The whole genome sequencing of the long-cultured strains identified many mutations, and some mutations were commonly found in all three long-cultured strains. The knockout strain of one of the commonly mutated genes, tagF, in the ancestral strain lost the ability to revert to walled state (rod shape), supporting that eliminating the function of tagF gene is one of the possible methods to convert unstable L forms to a stable state.

著者

Naoya Shimada Yukiko Okuda Kaisei Maeda Daisuke Umeno Shinichi Takaichi Masahiko Ikeuchi

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2020.01.003, (Released:2020-03-25)

参考文献数

24

被引用文献数

9

---

Heterologous production of a useful carotenoid astaxanthin was achieved in a cyanobacterium Synechocystis sp. PCC 6803 with the aid of marine bacterial genes. Astaxanthin and its intermediates emerged at high levels, whereas β-carotene and zeaxanthin disappeared in the strain. Total carotenoid accumulation was nearly two fold compared with wild type. The astaxanthin-producing strain was capable of only growing heterotrophically, which was likely due to the absence of β-carotene. Further enhanced accumulation was pursued by gene overexpression for possible rate-limiting steps in the biosynthesis pathway.

著者

Thi Huyen Do Ngoc Giang Le Trong Khoa Dao Thi Mai Phuong Nguyen Tung Lam Le Han Ly Luu Khanh Hoang Viet Nguyen Van Lam Nguyen Lan Anh Le Thu Nguyet Phung Nico M. van Straalen Dick Roelofs Nam Hai Truong

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2017.08.004, (Released:2018-03-12)

参考文献数

55

被引用文献数

11

---

The scarcity of enzymes having an optimal activity in lignocellulose deconstruction is an obstacle for industrial-scale conversion of cellulosic biomass into biofuels. With the aim of mining novel lignocellulolytic enzymes, a ~9 Gb metagenome of bacteria in Vietnamese native goats’ rumen was sequenced by Illumina platform. From the data, 821 ORFs encoding carbohydrate esterases (CEs) and polysaccharide lyases (PLs) serving for lignocellulose pre-treatment, 816 ORFs encoding 11 glycoside hydrolase families (GHs) of cellulases, and 2252 ORFs encoding 22 GHs of hemicellulases, were mined. The carbohydrate binding module (CBM) was also abundant with 763 ORFs, of which 480 ORFs are located with lignocellulolytic enzymes. The enzyme modularity analysis showed that CBMs are usually present in endoglucanase, endo 1,3-beta-D-glucosidase, and endoxylanase, whereas fibronectin 3-like module (FN3) mainly represents in GH3 and immunoglobulin-like domain (Ig) was located in GH9 only. Every domain located in each ORF was analyzed in detail to contribute enzymes’ modularity which is valuable for modelling, to study the structure, and for recombinant production. With the aim of confirming the annotated results, a mined ORF encoding CBM63 was highly expressed in E. coli in soluble form. The purified recombinant CBM63 exhibited no cellulase activity, but enhanced a commercial cellulase activity in the destruction of a paper filter.

著者

Yuzo Yamada Pattaraporn Yukphan Huong Thi Lan Vu Yuki Muramatsu Duangjai Ochaikul Somboon Tanasupawat Yasuyoshi Nakagawa

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.58, no.5, pp.397-404, 2012 (Released:2012-11-13)

参考文献数

28

被引用文献数

237

著者

Naoya Shimada Yukiko Okuda Kaisei Maeda Daisuke Umeno Shinichi Takaichi Masahiko Ikeuchi

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.66, no.2, pp.116-120, 2020 (Released:2020-06-17)

参考文献数

24

被引用文献数

2 9

---

Heterologous production of a useful carotenoid astaxanthin was achieved in a cyanobacterium Synechocystis sp. PCC 6803 with the aid of marine bacterial genes. Astaxanthin and its intermediates emerged at high levels, whereas β-carotene and zeaxanthin disappeared in the strain. Total carotenoid accumulation was nearly two fold compared with wild type. The astaxanthin-producing strain was capable of only growing heterotrophically, which was likely due to the absence of β-carotene. Further enhanced accumulation was pursued by gene overexpression for possible rate-limiting steps in the biosynthesis pathway.

著者

Yu Shinjyo Naoya Midorikawa Takashi Matsumoto Yuki Sugaya Yoshiki Ozawa Ayumi Oana Chiaki Horie Hirofumi Yoshikawa Yasuhiro Takahashi Toshio Hasegawa Kei Asai

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.68, no.2, pp.62-70, 2022 (Released:2022-09-15)

参考文献数

62

被引用文献数

1

---

Recently, the antibacterial effects of essential oils have been investigated in addition to their therapeutic purposes. Owing to their hydrophobic nature, they are thought to perturb the integrity of the bacterial cell membrane, leading to cell death. Against such antibiotic challenges, bacteria develop mechanisms for cell envelope stress responses (CESR). In Bacillus subtilis, a gram-positive sporulating soil bacterium, the extracytoplasmic function (ECF) sigma factor-mediated response system plays a pivotal role in CESR. Among them, σM is strongly involved in response to cell envelope stress, including a shortage of available bactoprenol. Vetiver essential oil, a product of Chrysopogon zizanioides (L.) Roberty root, is also known to possess bactericidal activity. σM was exclusively and strongly induced when the cells were exposed to Vetiver extract, and depletion of multi-ECF sigma factors (ΔsigM, ΔsigW, ΔsigX, and ΔsigV) enhanced sensitivity to it. From this quadruple mutant strain, the suppressor strains, which restored resistance to the bactericidal activity of Vetiver extract, emerged, although attempts to obtain resistant strains from the wild type did not succeed. Whole-genome resequencing of the suppressor strains and genetic analysis revealed inactivation of xseB or pnpA, which code for exodeoxyribonuclease or polynucleotide phosphorylase, respectively. This allowed the quadruple mutant strain to escape from cell death caused by Vetiver extract. Composition analysis suggested that the sesquiterpene, khusimol, might contribute to the bactericidal activity of the Vetiver extract.

著者

Toshio Sakamoto Yang Wei Koki Yuasa Yoshitaka Nishiyama

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2022.01.003, (Released:2022-05-20)

参考文献数

31

被引用文献数

1

---

The terrestrial cyanobacterium Nostoc commune is an anhydrobiotic organism with extreme longevity. Recovery of photosynthesis by rehydration was examined using our laboratory stocks of dry N. commune thalli after long-term storage in a desiccated state. In the samples stored at room temperature for over 8 years, photosynthetic oxygen evolution was barely detectable, whereas oxygen consumption was recovered. There was an exceptional case in which photosynthetic oxygen evolution recovered after 8 years of storage at room temperature. Both photosynthetic oxygen evolution and respiratory oxygen consumption were recovered in dry thalli stored at -20°C for over 15 years. Consistent with the recovery of photosynthetic oxygen evolution, Fv/Fm was detected in the samples stored at -20°C at levels similar to those of freshly collected N. commune colonies. Carotenoids, scytonemin and chlorophyll a appeared to be intact in the dry thalli stored at -20°C, but β-carotene was not detected in the samples stored at room temperature. α-Tocopherol was intact in the samples stored at -20°C but was degraded in the samples stored at room temperature. These results suggest that dry thalli of N. commune are capable of sustaining biological activities for a long time, although they are gradually damaged when stored at room temperature.

著者

Yuki Sugimoto Shinji Masuda

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2020.06.001, (Released:2020-12-21)

参考文献数

29

被引用文献数

3

---

Phototaxis is a phenomenon where cyanobacteria move toward a light source. Previous studies have shown that the blue-light-using-flavin (BLUF)-type photoreceptor PixD and the response regulator-like protein PixE control the phototaxis in the cyanobacterium Synechocystis sp. PCC6803. The pixD-null mutant moves away from light, whereas WT, pixE mutant, and pixD-pixE double mutant move toward the light. This indicates that PixE functions downstream of PixD and influences the direction of movement. However, it is still unclear how the light signal received by PixD is transmitted to PixE, and then subsequently transmitted to the type IV pili motor mechanism. Here, we investigated intracellular localization and oligomerization of PixD and PixE to elucidate mechanisms of phototaxis regulation. Blue-native PAGE analysis, coupled with western blotting, indicated that most PixD exist as a dimer in soluble fractions, whereas PixE localized in ~250 kDa and ~450 kDa protein complexes in membrane fractions. When blue-native PAGE was performed after illuminating the membrane fractions with blue light, PixE levels in the ~250 kDa and ~450 kDa complexes were reduced and increased, respectively. These results suggest that PixE, localized in the ~450 kDa complex, controls activity of the motor ATPase PilB1 to regulate pilus motility.

著者

Katsuhiko Okada Shoko Fujiwara Mikio Tsuzuki

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2020.02.002, (Released:2020-04-24)

参考文献数

96

被引用文献数

10

---

Photosynthesis is a biological process of energy conversion from solar radiation to useful organic compounds for the photosynthetic organisms themselves. It, thereby, also plays a role of food production for almost all animals on the Earth. The utilization of photosynthesis as an artificial carbon cycle is also attracting a lot of attention regarding its benefits for human life. Hydrogen and biofuels, obtained from photosynthetic microorganisms, such as microalgae and cyanobacteria, will be promising products as energy and material resources. Considering that the efficiency of bioenergy production is insufficient to replace fossil fuels at present, techniques for the industrial utilization of photosynthesis processes need to be developed intensively. Increase in the efficiency of photosynthesis, the yields of target substances, and the growth rates of algae and cyanobacteria must be subjects for efficient industrialization. Here, we overview the whole aspect of the energy production from photosynthesis to biomass production of various photosynthetic microorganisms.

著者

Akira Yasuda Daichi Inami Mitsumasa Hanaoka

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2020.01.010, (Released:2020-04-07)

参考文献数

31

被引用文献数

4

---

In cyanobacteria, transcription of a set of genes is specifically induced by high-light-stress conditions. In previous studies, RpaB, a response regulator of the two-component system, was shown to be involved in this regulation in vitro and in vivo. In this study, we examined whether RpaB-dependent transcriptional regulation was extensively observed, not only under high-light-stress conditions but also under various light intensities. Transcription of high-light-dependent genes hliA, nblA and rpoD3 was transiently and drastically induced during a dark-to-light shift in a manner similar to high-light-stress responses. Moreover, expression of these genes was activated under various light-intensity upshift conditions. Phos-tag SDS-PAGE experiments showed that the phosphorylation level of RpaB was decreased along with transcriptional induction of target genes in all of the light environments examined herein. These results suggest that RpaB may be widely involved in transcriptional regulation under dark-to-light and light-intensity upshift conditions and that high-light-responsive genes may be required in various light conditions other than high-light condition. Furthermore, it is hypothesised that RpaB is regulated by redox-dependent signals rather than by high-light-stress-dependent signals.

著者

Kazuki Nagata Katsuaki Oyama Atsushi Ota Chihiro Azai Kazuki Terauchi

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2020.01.008, (Released:2020-03-30)

参考文献数

31

被引用文献数

3

---

The cyanobacterial circadian oscillator can be reconstituted by mixing the purified clock proteins KaiA, KaiB, and KaiC with ATP in vitro, leading to a 24-h oscillation of KaiC phosphorylation. The cyanobacterial mutant pr1 carrying valine instead of alanine at position 422 of KaiC (KaiC-A422V) lost the ability to shift the phase of the circadian rhythm. In this study, we analyzed KaiC-A422V to investigate the effect of this single-residue substitution on the in vitro reconstitution of KaiC oscillation. KaiC-A422V exhibited low amplitude oscillations of phosphorylation with a smaller amount of Kai complex than wild-type KaiC (KaiC-WT). Although KaiA can stimulate KaiC phosphorylation, the phosphorylation level of KaiC-A422V is much lower than that of KaiC-WT even at higher KaiA concentrations. It has been suggested that monomer shuffling of KaiC is involved in entraining the in vitro rhythm. To examine whether KaiC-A422V has the capacity for monomer shuffling, we used the difference in the amplitude of the phosphorylation rhythms between KaiC-WT and KaiC-A422V as the indicator of monomer shuffling. When KaiC-A422V and KaiC-WT were mixed, the amplitude of the phosphorylation rhythm changed according to the mixing ratio. This suggests that KaiC-A422V has a reduced ability to shuffle monomers in hexameric KaiC. In addition, the A422V mutation resulted in a change of the stability of the KaiC protein.

著者

Hiroshi Kobayashi Hiromi Saito Tomohito Kakegawa

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.46, no.5, pp.235-243, 2000 (Released:2005-11-04)

参考文献数

73

被引用文献数

31 32

---

Bacteria can inhabit a wide range of environmental conditions, including extremes in pH ranging from 1 to 11. The primary strategy employed by bacteria in acidic environments is to maintain a constant cytoplasmic pH value. However, many data demonstrate that bacteria can grow under conditions in which pH values are out of the range in which cytoplasmic pH is kept constant. Based on these observations, a novel notion was proposed that bacteria have strategies to survive even if the cytoplasm is acidified by low external pH. Under these conditions, bacteria are obliged to use acid-resistant systems, implying that multiple systems having the same physiological role are operating at different cytoplasmic pH values. If this is true, it is quite likely that bacteria have genes that are induced by environmental stimuli under different pH conditions. In fact, acid-inducible genes often respond to another factor(s) besides pH. Furthermore, distinct genes might be required for growth or survival at acid pH under different environmental conditions because functions of many systems are dependent on external conditions. Systems operating at acid pH have been described to date, but numerous genes remain to be identified that function to protect bacteria from an acid challenge. Identification and analysis of these genes is critical, not only to elucidate bacterial physiology, but also to increase the understanding of bacterial pathogenesis.

著者

Marta Sochocka Tomasz Tomczyk Maciej Sobczyński Bożena Szermer-Olearnik Janusz Boratyński

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.61, no.3, pp.75-81, 2015-06-30 (Released:2015-07-29)

参考文献数

36

被引用文献数

5 7

---

The aim of this study was to develop a minimal medium for the cultivation of Escherichia coli B, which could be especially suitable for the industrial propagation of bacteriophage T4. The new defined, minimal SM-1 culture medium, contains free amino acids as the only nitrogen source and enables the bacteria generation time to be prolonged and satisfactory phage titers to be achieved. The presence of organic ingredients, such as meat extracts, yeast hydrolysates, enzymatic protein hydrolysates, in a culture medium may cause problems in the case of bacteria or phage cultures for therapeutic purposes. In the present study, we introduce a new medium, together with some procedures and applications for its usage. We also present new kinetics of E. coli B growth. Some traits such as the lack of high molecular proteins, a bacterial growth comparable to that in a rich medium, and the cost effectiveness of the medium, makes it highly competitive with currently used microbiological media. The surprisingly high titers of bacteriophage T4 obtained in our experiments suggest that SM-1 medium has the potential to find a broad application in medicine, especially in infectious disease therapy, pharmacy and biotechnology.

著者

YOKO YAMAMOTO ATSUSHI WATANABE

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.20, no.2, pp.83-86, 1974 (Released:2006-08-16)

参考文献数

8

被引用文献数

14 16

---

The fatty acid composition of lichens and their symbionts was determined. In lichens, linoleic and oleic acids were the most abundant and these acids were also rich in their phyco- and mycobionts. A small amount of arachidonic acid was detected in some of the lichens and their phyco- and mycobionts.

著者

Hazuki Hasegawa Kan Tanaka

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

pp.2023.02.001, (Released:2023-02-17)

参考文献数

20

---

Certain mutations of the model cyanobacterium Synechococcus elongatus PCC 7942 during laboratory storage have resulted in some divergent phenotypes. One laboratory stored strain (H1) shows a temperature-sensitive (ts) growth phenotype at 40 °C. Here, we investigated the reason for this temperature sensitivity. Whole genome sequencing of H1 identified a single nucleotide mutation in synpcc7942_R0040 encoding tRNA-Leu(CAA). The mutation decreases the length of the tRNA-Leu t-arm from 5 to 4 base pairs, and this explains the ts phenotype. Secondary mutations suppressing the ts phenotype were identified in synpcc7942_1640, which putatively encodes a NYN domain-containing protein (nynA). The NYN domain is thought to be involved in tRNA/rRNA degradation. Thus, the structural stability of tRNA-Leu is critical for growth at 40 °C in Synechococcus elongatus PCC 7942.

著者

Hidetoshi Inoue Kumiko Tajima Cristina Mitsumori Natsuko Inoue-Kashino Takamasa Miura Kentaro Ifuku Ryuichi Hirota Yasuhiro Kashino Katsutoshi Fujita Hiroshi Kinoshita

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.68, no.3, pp.151-162, 2022 (Released:2022-11-10)

参考文献数

36

被引用文献数

1

---

A genetically modified (GM) strain of the diatom Chaetoceros gracilis expressing the phosphite dehydrogenase gene (ptxD), which is a useful gene both for the biological containment and the avoidance of microbial contamination, was characterized to estimate the risk against the biodiversity by laboratory experiments. GM strain could grow in the medium containing phosphite as a sole source of phosphorus, while its general characteristics such as growth, salt tolerance, heat and dehydration resistance in the normal phosphate-containing medium were equivalent to those of wild type (WT) strain. The increase in potential toxicity of GM strain against plant, crustacean, fish and mammal was also disproved. The dispersal ability of WT strain cultured in an outdoor raceway pond was investigated for 28 days by detecting the psb31 gene in vessels, settled at variable distances (between 5 and 60 m) from the pond. The diatom was detected only in one vessel placed 5 m apart. To estimate the influence on the environment, WT and GM strains were inoculated into freshwater, seawater and soil. The influence on the microbiome in those samples was assessed by 16S rRNA gene amplicon sequencing, in addition to the analysis of the survivability of those strains in the freshwater and the seawater. The results indicated that the effect to the microbiome and the survivability were comparable between WT and GM strains. All results showed that the introduction of the ptxD gene into the diatom had a low risk on biodiversity.

著者

MONIKA ZIPPEL MARLIES NEIGENFIND

出版者

Applied Microbiology, Molecular and Cellular Biosciences Research Foundation

雑誌

The Journal of General and Applied Microbiology (ISSN:00221260)

巻号頁・発行日

vol.34, no.1, pp.7-14, 1988 (Released:2006-08-18)

参考文献数

20

被引用文献数

1 7

---

Three methods for preserving 16 Streptornyces strains were tested: lyophilization on soil and storage in frozen glycerol medium (-20°C), and in liquid nitrogen (-196°C) in the presence of dimethyl sulfoxide. The viability, stability of auxotrophic markers, antibiotic production, and resistance to their own antibiotics for a period up to one year were studied. No variations in the production of and resistance to antibiotics or accumulation of revertants of mutants were evident during the toral preservation time in all three storage methods. A drastic decrease in viable counts was observed after lyophilization on soil. Viability of strains frozen in glycerol and after storage in liquid nitrogen was similar and ranged from 2.3% to 36.6%.Storage of streptomycetes in frozen glycerol is recommended as a quick and reliable method for frequent studies in the laboratory. Storage in liquid nitrogen is recommended as a long-term preservation method.