Minimal Requirements for Commitment to Sporulation in
            <i>Bacillus megaterium</i>

Greene, Richard A.; Slepecky, Ralph A.

doi:10.1128/jb.111.2.557-565.1972

Cited by 23 publications

(8 citation statements)

References 22 publications

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“…This explanation implies that sporulation loci remain sus-BACTERIAL ENDOSPORE FORMATION 935 ceptible to repression by catabolites, at least until the time of commitment. The point of commitment with respect to addition of fresh broth to sporulating cells has generally been found to be at the stage of protoplast formation (stage III: 81,95,108,128). It is clear that the precise point at which commitment occurs depends on the medium in which the cells are sporulating and on the enriching medium used (94).…”

Section: Analysis Of Merodiploidsmentioning

confidence: 99%

Genetic aspects of bacterial endospore formation.

Piggot¹,

Coote²

1976

Bacteriological Reviews

405

283

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95 cysA14 60 ery-1 25 purA 49 metC3; 21 ura-1 c 42 ura-26 s 83 ura-1; 5 metC3 ' 54 lys-l' 44 trpC2 35 trpC2 33 Iys-1; 16 trpC2 56 lys-1 25 phe-1; 10 ilvCl RI = 0.1 12 hisAI RI s 0.2 47 ura-1; 1 metC3 12 ura-26 16 ura-1; 49 metC3 49 52 148 307 24 phe-12; 1 lys-l 49 B 49 49, 143, 334 49 244 49 a Linkage with vegetative markers is expressed as % cotransfer. Linkage between spo mutations is expressed as the recombination index (RI [170]). b A, J.A. Hoch, personal communication; B, M. Young, personal communication; C, P.J. Piggot, unpublished observations. I Assignment to locus is not certain, see text. d If 94U (reference 148) is the same as 94 (reference 257), then this has the same phenotype as spoIVC mutants described by Coote (49, 50), and the mutations should be placed in the spoIVC locus.

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Section: Analysis Of Merodiploidsmentioning

confidence: 99%

Genetic aspects of bacterial endospore formation.

Piggot¹,

Coote²

1976

Bacteriological Reviews

405

283

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“…At the commitment point, induced phage were trapped and carried into spores which germinated to give infectious centers. The spontaneous derepression of phage at a time which blocked spore formation led to 7 x 10O infectious centers per ml and would not normally be noticed. Derepression at the time of phage entrapment was not observed to occur without induction with mitomycin C. Sporulating cells are committed if they can-earlier B. subtilis commitment time (6,17).…”

mentioning

confidence: 98%

Exclusion of Induced Bacteriophage from Cells of a Lysogenic Bacillus megaterium Committed to Sporulation

Hendry

Fitz-James

1974

J Bacteriol

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Spontaneous release of the temperate bacteriophage T (φT), carried by Bacillus megaterium 899a, occurred during early growth of the host cells. Rejuvenated cells (accomplished by a 5× dilution in fresh medium) and unrejuvenated cells were induced by mitomycin C during the course of sporulation and subsequent phage φT production measured by burst size. Induction of sequential samples of unrejuvenated cells resulted in burst sizes that fell to zero as T 0 sporulation time in the main culture was approached. This drop in burst size was not considered a sporulation event, as it also occurred during analogous stages of growth in an asporogenous mutant. Rejuvenated, induced portions of the culture of sporulating cells of B. megaterium 899a gave large burst sizes until T +2 , when the burst sizes fell to zero. The stage I asporogenous mutant, treated in a similar manner, gave lower, but still substantial, burst sizes; thus, the sharp decline in burst size of induced rejuvenated sporulating cells appeared to be a sporulation event. Sporulating cells induced at times shortly after T 1.5 formed spores in which the induced phage were trapped until germination of the spores, which formed infectious centers. This induced phage-trapping was maximal when the sporulating cultures were induced at T 2.25 . Commitment to sporulation could be defined by our system as that point beyond which rejuvenated sporulating cells were unable to support the replication of the phage. This point also correlated with the increase in induced phage-trapping by spores. Two other methods gave a similar commitment time. Commitment to sporulation, in spite of added glucose or fresh complex medium, occurred at the same time. Electron micrography showed that the committed cell was still undergoing engulfment. The fate of induced phage φT was determined at different points during growth and sporulation. Induction at times prior to T 0 , which were longer than the eclipse period of the phage, resulted in a burst size of approximately 50. At times prior to T 0 , shorter than the phage eclipse period, induction led to lysis with low burst sizes, approaching zero. The pattern of spontaneous phage release during growth was similar. From T 0 up to the point of commitment to sporulation, induction resulted in the blocking of spore formation without lysis. At the commitment point, induced phage were trapped and carried into spores which germinated to give infectious centers. The spontaneous derepression of phage at a time which blocked spore formation led to 7 × 10 4 infectious centers per ml and would not normally be noticed. Derepression at the time of phage entrapment was not observed to occur without induction with mitomycin C.

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“…The metal ions likely played a role in activating enzyme systems necessary for sporulation (Kolodziej and Slepecky 1964 ). Manganese and iron are indispensable for sporulation and participate in the synthesis of Bacillus ’s secondary metabolites, such as antibiotics and peptides (Granger et al 2011 ; Greene and Slepecky 1972 ; Oh and Freese 1976 ). Calcium acts as an important component of spores by chelating with DPA (Ca-DPA) and helps to improve heat resistance (Levinson et al 1961 ).…”

Section: Discussionmentioning

confidence: 99%

Rapid optimization of spore production from Bacillus amyloliquefaciens in submerged cultures based on dipicolinic acid fluorimetry assay

Ren

Guo

2018

AMB Expr

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Some optimization techniques have been widely applied for spore fermentation based on the plate counting. This study optimized the culture medium for the spore production of Bacillus amyloliquefaciens BS-20 and investigated the feasibility of using a dipicolonic acid (DPA) fluorimetry assay as a simpler alternative to plate counting for evaluating spore yields. Through the single-factor experiment, the metal ions and agro-industrial raw materials that significantly enhanced spore production were determined. After conducting a response surface methodology (RSM) analysis of several metal ions, the combined use of optimum concentrations of Mn2+, Fe2+, and Ca2+ in culture media produced a 3.4-fold increase in spore yields. Subsequently, supplementing soybean meal and corn meal with optimum concentrations determined by another RSM analysis produced an 8.8-fold increase. The final spore concentration from a culture medium incorporating optimum concentrations of the metal ions and raw materials mentioned above was verified to reach (8.05 ± 0.70) × 109 CFU/mL by both DPA fluorimetry and plate counting. The results suggest that the use of DPA fluorescence intensity as an alternative value to colony counting provides a general method for assessing spore yields with less work and shorter time.

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Minimal Requirements for Commitment to Sporulation in Bacillus megaterium

Cited by 23 publications

References 22 publications

Genetic aspects of bacterial endospore formation.

Genetic aspects of bacterial endospore formation.

Exclusion of Induced Bacteriophage from Cells of a Lysogenic Bacillus megaterium Committed to Sporulation

Rapid optimization of spore production from Bacillus amyloliquefaciens in submerged cultures based on dipicolinic acid fluorimetry assay

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