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2022 ◽  
Vol 12 ◽  
Author(s):  
Jackson Luu ◽  
Connor M. Mott ◽  
Olivia R. Schreiber ◽  
Holly M. Giovinco ◽  
Melanie Betchen ◽  
...  

Bacillus subtilis produces dormant, highly resistant endospores in response to extreme environmental stresses or starvation. These spores are capable of persisting in harsh environments for many years, even decades, without essential nutrients. Part of the reason that these spores can survive such extreme conditions is because their chromosomal DNA is well protected from environmental insults. The α/β-type small acid-soluble proteins (SASPs) coat the spore chromosome, which leads to condensation and protection from such insults. The histone-like protein HBsu has been implicated in the packaging of the spore chromosome and is believed to be important in modulating SASP-mediated alterations to the DNA, including supercoiling and stiffness. Previously, we demonstrated that HBsu is acetylated at seven lysine residues, and one physiological function of acetylation is to regulate chromosomal compaction. Here, we investigate if the process of sporulation or the resistance properties of mature spores are influenced by the acetylation state of HBsu. Using our collection of point mutations that mimic the acetylated and unacetylated forms of HBsu, we first determined if acetylation affects the process of sporulation, by determining the overall sporulation frequencies. We found that specific mutations led to decreases in sporulation frequency, suggesting that acetylation of HBsu at some sites, but not all, is required to regulate the process of sporulation. Next, we determined if the spores produced from the mutant strains were more susceptible to heat, ultraviolet (UV) radiation and formaldehyde exposure. We again found that altering acetylation at specific sites led to less resistance to these stresses, suggesting that proper HBsu acetylation is important for chromosomal packaging and protection in the mature spore. Interestingly, the specific acetylation patterns were different for the sporulation process and resistance properties of spores, which is consistent with the notion that a histone-like code exists in bacteria. We propose that specific acetylation patterns of HBsu are required to ensure proper chromosomal arrangement, packaging, and protection during the process of sporulation.


2021 ◽  
Vol 6 (1) ◽  
pp. 102-110
Author(s):  
Rudy Hermawan ◽  
Laifa Fusvita ◽  
Naufal Hafizh Nugraha ◽  
Mega Putri Amelya

Lysurus is one of the unique genera in Basidiomycetes. It has a stinky odor and slime on the head. The unusual-shaped makes the species in Lysurus easily to be identified. One of Lysurus had been found in West Java, Indonesia namely L. periphragmoides. The specimen was deposited into Herbarium Bogoriense with code BO 24418. This study aimed to obtain specimens and characterize the Lysurus BO 24418 using morphological characteristics, and analyze the phenetic relationship among Lysurus species. Lysurus BO 24418 has two phases (egg and mushroom). The egg phase is usually hypogeous underground. The mushroom has a head and stem. The head bears the mature spore with slime distribute malodor. The stem has a hollow and spongy texture with a yellowish color. The numerical data of morphological characters of species in Lysurus were analyzed using NTSys ver 2.1 software. Ten characters were used to build a dendrogram using Sequential Agglomerative Hierarchical Nested (SAHN) cluster analysis with Unweighted Pair Group Method with Arithmetic Mean (UPGMA). Phallus indusiatus was selected as an outgroup. The analyses showed the specimen was classified as L. periphragmoides with 100% of similarity coefficient and it was close L. gardneri with 40,4% of similarity coefficient. The characters that cluster among them are stem surface, head type, egg diameter, and spore max length


mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Jihong Li ◽  
Bruce A. McClane

ABSTRACT Clostridium perfringens type F food poisoning (FP) strains cause one of the most common foodborne illnesses. This FP develops when type F FP strains sporulate in the intestines and produce C. perfringens enterotoxin (CPE), which is responsible for the diarrhea and abdominal cramps of this disease. While C. perfringens can produce up to three different sialidases, the current study surveyed FP strains, which confirmed the results of a previous study that they consistently carry the nanH sialidase gene, often as their only sialidase gene. NanH production was found to be associated with sporulating cultures of the surveyed type F FP strains, including SM101 (a transformable derivative of a FP strain). The sporulation-associated regulation of NanH production by strain SM101 growing in modified Duncan-Strong medium (MDS) was shown to involve Spo0A, but it did not require the completion of sporulation. NanH production was not necessary for either the growth or sporulation of SM101 when cultured in MDS. In those MDS cultures, NanH accumulated in the sporulating mother cell until it was released coincidently with CPE. Since CPE becomes extracellular when mother cells lyse to release their mature spores, this indicates that mother cell lysis is also important for NanH release. The copresence of NanH and CPE in supernatants from lysed sporulating cultures was shown to enhance CPE cytotoxicity for Caco-2 cells. This enhancement was attributable to NanH increasing CPE binding and could be replicated with purified recombinant NanH. These in vitro findings suggest that NanH may be an accessory virulence factor during type F FP. IMPORTANCE Clostridium perfringens type F strains cause the second most common bacterial foodborne illness in the United States. C. perfringens enterotoxin (CPE) is responsible for the diarrhea and cramping symptoms of this food poisoning (FP). Previous studies showed that NanI sialidase can enhance CPE activity in vitro. While many type F FP strains do not produce NanI, they do consistently make NanH sialidase. This study shows that, like CPE, NanH is produced by sporulating type F FP strains and then released extracellularly when their sporulating cells lyse to release their mature spore. NanH was shown to enhance CPE cytotoxicity in vitro by increasing CPE binding to cultured Caco-2 cells. This enhancement could be important because many type F FP strains produce less CPE than necessary (in a purified form) to cause intestinal pathology in animal models. Therefore, NanH represents a potential accessory virulence factor for type F FP.


2021 ◽  
Vol 8 ◽  
Author(s):  
Vera Brekhman ◽  
Maya Ofek-Lalzar ◽  
Stephen D. Atkinson ◽  
Gema Alama-Bermejo ◽  
Keren Maor-Landaw ◽  
...  

Myxozoans are widely distributed aquatic obligate endoparasites that were recently recognized as belonging within the phylum Cnidaria. They have complex life cycles with waterborne transmission stages: resistant, infectious spores that are unique to myxozoans. However, little is known about the processes that give rise to these transmission stages. To understand the molecular underpinnings of spore formation, we conducted proteomics on Ceratonova shasta, a highly pathogenic myxozoan that causes severe mortalities in wild and hatchery-reared salmonid fishes. We compared proteomic profiles between developmental stages from inside the fish host, and the mature myxospore, which is released into the water where it drifts passively, ready to infect the next host. We found that C. shasta contains 2,123 proteins; representing the first proteomic catalog of a myxozoan myxospore. Analysis of proteins differentially expressed between developing and mature spore stages uncovered processes that are active during spore formation. Our data highlight dynamic changes in the actin cytoskeleton, which provides myxozoan developmental stages with mobility through lamellipodia and filopodia, whereas in the mature myxospore the actin network supports F-actin stabilization that reinforces the transmission stage. These findings provide molecular insight into the myxozoan life cycle stages and, particularly, into the process of sporogenesis.


2021 ◽  
Vol 265 ◽  
pp. 04008
Author(s):  
Thi Tuyen Do ◽  
Van Thang Le ◽  
Cao Cuong Ngo ◽  
Thi Thu Hong Do ◽  
Thi Hong Phuong Dang

Compost is a highly humified organic fertilizer, rich in nutrients and a source of a variety of aerobic microorganisms, including actinomycetes, which develop in response to different levels of temperature, humidity, oxygen and pH. Microbes growing on the compost are believed to have the ability to produce extracellular hydrolytic enzymes. The purpose of this study was to determine the ability of thermophilic actinomycetes XM21 isolated from compost in producing hydrolytic enzymes, namely cellulase, amylase, protease, and lipase. The confirmation tests of hydrolytic enzymes-producing ability were conducted by inoculating the microbes into media containing cellulose, starch, gelatin and tween 80, using the method of disc diffusion. The results showed that strain XM21 capable of extracellular enzymes producing, such as cellulase, protease, amylase, lipase. Strain XM21 can grow well with high cellulase activity in a wide range of temperature between 30-55oC, optimum at 45oC. The strain can grow well on different media, utilized carbon sources with pH 5-10, and salinity of 0-5%. On the agar plate, the strain has white aerial mycelia, the mature spore chains appeared spirals, moderately long, bearing 10 to 35 spores each. Based on the biological characteristics and phylogenetic analysis of 16S rDNA, it can be concluded that strain XM21 is close to Streptomyces flavovariabilis (98, 12%), hence identified as Streptomyces flavovariabilis XM21.


Antibiotics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 847
Author(s):  
Elodie Tenconi ◽  
Matthew Traxler ◽  
Déborah Tellatin ◽  
Gilles P. van Wezel ◽  
Sébastien Rigali

Bioactive natural products are typically secreted by the producer strain. Besides that, this allows the targeting of competitors, also filling a protective role, reducing the chance of self-killing. Surprisingly, DNA-degrading and membrane damaging prodiginines (PdGs) are only produced intracellularly, and are required for the onset of the second round of programmed cell death (PCD) in Streptomyces coelicolor. In this work, we investigated the influence of PdGs on the timing of the morphological differentiation of S. coelicolor. The deletion of the transcriptional activator gene redD that activates the red cluster for PdGs or nutrient-mediated reduction of PdG synthesis both resulted in the precocious appearance of mature spore chains. Transcriptional analysis revealed an accelerated expression of key developmental genes in the redD null mutant, including bldN for the developmental σ factor BldN which is essential for aerial mycelium formation. In contrast, PdG overproduction due to the enhanced copy number of redD resulted in a delay or block in sporulation. In addition, confocal fluorescence microscopy revealed that the earliest aerial hyphae do not produce PdGs. This suggests that filaments that eventually differentiate into spore chains and are hence required for survival of the colony, are excluded from the second round of PCD induced by PdGs. We propose that one of the roles of PdGs would be to delay the entrance of S. coelicolor into the dormancy state (sporulation) by inducing the leakage of the intracellular content of dying filaments thereby providing nutrients for the survivors.


2019 ◽  
pp. 12-29
Author(s):  
R.A. Sidorov ◽  
A.Yu. Starikov ◽  
A.S. Voronkov ◽  
A.S. Medvedeva ◽  
Z.V. Krivova ◽  
...  

As a result of screening of spore-forming bacteria, a B-13186 strain with a wide spectrum of antagonistic activity identified as Brevibacillus laterosporus by the analysis of sequences of variable sites of 16S rRNA was selected. Morphological, cultural and biochemical characteristics of the strain were studied. A distinctive feature of the strain is the presence of a canoe-like inclusion formed in sporangia and attached to the mature spore, as well as the ability to synthesize round-shaped crystalline inclusions. The strain was shown to be active against various species of gram-positive bacteria including A search for strains capable of simultaneously producing high amounts of several biologically valuable compounds and/or having high biomass productivity has been carried out. The growth characteristics and biochemical composition of 12 microalgae and cyanobacteria strains from the IPPAS Collection in the exponential and stationary growth phases were studied. All the strains had high growth rates (doubling time 6-22 h). The strains of Cyanobacterium sp. IPPAS B-1200, Chlorella sp. IPPAS C-1210, Nannochloris sp. IPPAS C-1509, Cyanidium caldarium IPPAS P-510 and Vischeria sp. IPPAS H-242 demonstrated the highest biotechnological potential and can be used for the production of various types of biofuel, pigments, feed and food additives, including those with high content of eicosapentaenoic (20:5 Δ5,8,11,14,17) acid content. microalgae, cyanobacteria, biochemical composition, fatty acids, valuable metabolites, growth characteristics This work was supported by a grant from the Russian Science Foundation [no. 14-14-00904]


2019 ◽  
pp. 3-11
Author(s):  
N.I. Kuznetsova ◽  
M.A. Nikolaenko ◽  
O.V. Bunina ◽  
R.R. Azizbekyan

As a result of screening of spore-forming bacteria, a B-13186 strain with a wide spectrum of antagonistic activity identified as Brevibacillus laterosporus by the analysis of sequences of variable sites of 16S rRNA was selected. Morphological, cultural and biochemical characteristics of the strain were studied. A distinctive feature of the strain is the presence of a canoe-like inclusion formed in sporangia and attached to the mature spore, as well as the ability to synthesize round-shaped crystalline inclusions. The strain was shown to be active against various species of gram-positive bacteria including S. aureus (MRSA), against phytopathogenic fungi Fusarium solani, Sclerotinia sclerotiorum, Phoma solanicola, Rhizoctonia solani and Botrytis cinerea and against microalgae Nostoc spp., Anabaena spp., Microсystis spp., Chlorella spp., Amorphonostoc spp. and Synechocystis spp. Brevibacillus laterosporus, spore-forming bacteria, microalgae, phytopathogenic fungi, crystalline inclusions.


2018 ◽  
Vol 63 (3) ◽  
pp. 495-503 ◽  
Author(s):  
Letícia P. Vidal ◽  
Douglas McIntosh ◽  
José L. Luque

Abstract During a parasitological survey of Astyanax altiparanae captured in the Mogi Guaçú river, Pirassununga, state of São Paulo, Brazil, a new species of myxozoa was observed infecting the kidney of 30 of 42 specimens. Plasmodia of the new myxozoa, referred to herein as Unicauda whippsi n. sp. were spherical and varied from 450 to 1000 μm in length. The mature spore was elongated and measured 11 ± 1.2 (10–12) μm long by 5.4 ± 0.6 (4.7–7.2) μm wide. Polar capsules of unequal length with the filament coiled 7–9 times and a unique caudal process characteristic of the genus Unicauda, were recorded. Phylogenetic analysis demonstrated that U. whippsi n. sp. clustered with members of the genus Unicauda and Myxobolus, confirming it’s placement within the family Myxobolidae. This is the first record of a species of Unicauda infecting characiform fish, as well as the first registered occurrence of species of this genus in South America.


2011 ◽  
Vol 56 (3) ◽  
Author(s):  
Abdel-Azeem Abdel-Baki

AbstractA new myxosporean, Myxobolus egyptica sp. nov., was described from the gills of the hornlip mullet Oedalechilus labiosus, collected from the Red Sea at Al-Quseir city, Egypt. The prevalence of infection was 12/72 (16.66%). Myxobolus egyptica was identified on the basis of spore morphometry, histology and transmission electron microscopy. It was distinguished from all previously reported Myxobolus spp. by its shape, dimensions of the mature spore 10.0 ± 0.6 (9.5–10.5) μm in length, 8.5 ± 0.4 (8.0–9.0) μm in width and 8.7 ± 0.5 (8.4–9.2) μm in thickness, polar capsules, locality and host. The parasite formed intrafilamental cyst-like plasmodia. These plasmodia caused curling and atrophy of the gill lamellae. The ultrastructural analysis revealed a double-unit plasmodial membrane which was in direct contact with the host cells and had numerous vesicles. Some mitochondria were found below this membrane. The disporic pansporoblast was earliest recognizable stage of sporogenesis. Advanced developmental stages of spores and mature spores were reported.


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