Revealing nutritional requirements of MICP-relevant Sporosarcina pasteurii DSM33 for growth improvement in chemically defined and complex media.

Microbial induced calcite precipitation (MICP) based on ureolysis has a high potential for many applications, e.g. restoration of construction materials. The gram-positive bacterium Sporosarcina pasteurii is the most commonly used microorganism for MICP due to its high ureolytic activity. However, Sporosarcina pasteurii is so far cultivated almost exclusively in complex media, which only results in moderate biomass concentrations at the best. Cultivation of Sporosarcina pasteurii must be strongly improved in order to make technological application of MICP economically feasible. The growth of Sporosarcina pasteurii DSM 33 was boosted by detecting auxotrophic deficiencies (L-methionine, L-cysteine, thiamine, nicotinic acid), nutritional requirements (phosphate, trace elements) and useful carbon sources (glucose, maltose, lactose, fructose, sucrose, acetate, L-proline, L-alanine). These were determined by microplate cultivations with online monitoring of biomass in a chemically defined medium and systematically omitting or substituting medium components. Persisting growth limitations were also detected, allowing further improvement of the chemically defined medium by the addition of glutamate group amino acids. Common complex media based on peptone and yeast extract were supplemented based on these findings. Optical density at the end of each cultivation of the improved peptone and yeast extract media roughly increased fivefold respectively. A maximum OD600 of 26.6 ± 0.7 (CDW: 17.1 ± 0.5 g/L) was reached with the improved yeast extract medium. Finally, culture performance and media improvement was analysed by measuring the oxygen transfer rate as well as the backscatter during shake flask cultivation.

A Preliminary Study on Probiotic Characteristics of Sporosarcina spp. for Poultry Applications.

Probiotics are well known for their wide range of beneficial activities. However, recent use of probiotic Bifidobacterium, Enterococcus, and Lactobacillus spp. has been plagued by certain disadvantages such as complex growth requirements, high maintenance cost, susceptibility to the gastrointestinal environment, pathogenic gene transfer, non-standardized dosage, cell lysis at extreme acidic pH, widespread antibiotic resistance, and lower bacterial viability due to the lack of spore formation. Therefore, spore-forming bacteria belonging to Sporosarcina genus such as pasteurii, globispora, and psychrophila were assessed for probiotic characteristics such as biofilm formation, intestinal adhesion, acid and bile tolerance, antibiotic sensitivity, and anti-pathogenic activity. This ensures bacterial viability under gastrointestinal conditions and enabled the same to colonize effectively in the intestinal lumen (in vitro). The bacterial cell counts ranging from 6.59 to 6.91 log(CFU/mL) was observed for Sporosarcina spp. after 16 h. This indicated that there is no significant difference in the cell counts (P-value = 0.90). The cell counts of Sporosarcina spp. ranging from 5.57 to 5.93 log(CFU/mL) displayed strong acid tolerance at pH 2. They were also viable at higher bile (0.5%) concentration. Among the Sporosarcina spp., pasteurii showed better tolerance (6.90 log(CFU/mL)) even after 16 h. Among the selected bacteria, Sporosarcina psychrophila was more susceptible to teicoplanin and meropenem with an inhibition zone of 30 mm. Maximum antagonistic activity was observed against Serratia marcescens (with inhibition zone up to 15 mm). Our results suggest that bacteria belonging to Sporosarcina genus possess all the required characteristics to be used as potential poultry probiotics.

Effect of Microorganism Sporosarcina pasteurii on the Hydration of Cement Paste.

Years of research have shown that the application of microorganisms increases the compressive strength of cement-based material when it is cured in a culture medium. Because the compressive strength is strongly affected by the hydration of cement paste, this research aimed to investigate the role of the microorganism Sporosarcina pasteurii in hydration of cement paste. The microorganism's role was investigated with and without the presence of a urea-CaCl2 culture medium (i.e., without curing the specimens in the culture medium). The results showed that S. pasteurii accelerated the early hydration of cement paste. The addition of the urea-CaCl2 culture medium also increased the speed of hydration. However, no clear evidence of microbially induced calcite precipitation appeared when the microorganisms were directly mixed with cement paste.

Sporosarcina siberiensis sp. nov., isolated from the East Siberian Sea.

A Gram-stain positive, non-motile, rod-shaped bacterium, designated strain 1111S-42(T), was isolated from the East Siberian Sea. The organism was found to grow at 4-30 °C, pH 7.0-8.5 and in 0-8 % (w/v) NaCl, with optimal growth occurring at 28 °C, pH 7.5 and in 1 % NaCl. Based on 16S rRNA gene sequence similarity studies, strain 1111S-42(T) was found to belong to the genus Sporosarcina and to be most closely related to Sporosarcina contaminans CCUG53915(T) (97.3 %) and Sporosarcina soli I80(T) (97.2 %). The main polar lipids were found to include diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant menaquinone was identified as MK-7. The major cellular fatty acids were identified as anteiso-C15:0 (34.4 %), iso-C15:0 (29.8 %) and anteiso-C17:0 (22.4 %). The DNA G+C content of strain 1111S-42(T) was determined to be 39 mol %. The values of DNA-DNA relatedness between the strain 1111S-42(T) and related type strains of the genus Sporosarcina were less than 30 %. Based on the phylogenetic analysis, along with extensive physiological and chemotaxonomic testing, we conclude that the bacterium represents a novel species of the genus Sporosarcina, for which the name Sporosarcina siberiensis sp. nov. is proposed. The type strain is strain 1111S-42(T) (=CGMCC 1.12516(T) = LMG 27494(T)).

Reciprocal influence of protein domains in the cold-adapted acyl aminoacyl peptidase from Sporosarcina psychrophila.

Acyl aminoacyl peptidases are two-domain proteins composed by a C-terminal catalytic α/ß-hydrolase domain and by an N-terminal ß-propeller domain connected through a structural element that is at the N-terminus in sequence but participates in the 3D structure of the C-domain. We investigated about the structural and functional interplay between the two domains and the bridge structure (in this case a single helix named α1-helix) in the cold-adapted enzyme from Sporosarcina psychrophila (SpAAP) using both protein variants in which entire domains were deleted and proteins carrying substitutions in the α1-helix. We found that in this enzyme the inter-domain connection dramatically affects the stability of both the whole enzyme and the ß-propeller. The α1-helix is required for the stability of the intact protein, as in other enzymes of the same family; however in this psychrophilic enzyme only, it destabilizes the isolated ß-propeller. A single charged residue (E10) in the α1-helix plays a major role for the stability of the whole structure. Overall, a strict interaction of the SpAAP domains seems to be mandatory for the preservation of their reciprocal structural integrity and may witness their co-evolution.

Potential CO2 leakage reduction through biofilm-induced calcium carbonate precipitation.

Mitigation strategies for sealing high permeability regions in cap rocks, such as fractures or improperly abandoned wells, are important considerations in the long term security of geologically stored carbon dioxide (CO(2)). Sealing technologies using low-viscosity fluids are advantageous in this context since they potentially reduce the necessary injection pressures and increase the radius of influence around injection wells. Using aqueous solutions and suspensions that can effectively promote microbially induced mineral precipitation is one such technology. Here we describe a strategy to homogenously distribute biofilm-induced calcium carbonate (CaCO(3)) precipitates in a 61 cm long sand-filled column and to seal a hydraulically fractured, 74 cm diameter Boyles Sandstone core. Sporosarcina pasteurii biofilms were established and an injection strategy developed to optimize CaCO(3) precipitation induced via microbial urea hydrolysis. Over the duration of the experiments, permeability decreased between 2 and 4 orders of magnitude in sand column and fractured core experiments, respectively. Additionally, after fracture sealing, the sandstone core withstood three times higher well bore pressure than during the initial fracturing event, which occurred prior to biofilm-induced CaCO(3) mineralization. These studies suggest biofilm-induced CaCO(3) precipitation technologies may potentially seal and strengthen fractures to mitigate CO(2) leakage potential.

Sporosarcina newyorkensis sp. nov. from clinical specimens and raw cow's milk.

Twelve independent isolates of a gram-positive, endospore-forming rod were recovered from clinical specimens in New York State, USA, and from raw milk in Flanders, Belgium. The 16S rRNA gene sequences for all isolates were identical. The closest species with a validly published name, based on 16S rRNA gene sequence, is Sporosarcina koreensis (97.13 % similarity). DNA-DNA hybridization studies demonstrate that the new isolates belong to a species distinct from their nearest phylogenetic neighbours. The partial sequences of the 23S rRNA gene for the novel strains and their nearest neighbours also provide support for the novel species designation. Maximum-likelihood phylogenetic analysis of the 16S rRNA gene sequences confirmed that the new isolates are in the genus Sporosarcina. The predominant menaquinone is MK-7, the peptidoglycan has the type A4α L-Lys-Gly-D-Glu, and the polar lipids consist of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The predominant fatty acids are iso-C(14 : 0), iso-C(15 : 0) and anteiso-C(15 : 0). In addition, biochemical and morphological analyses support designation of the twelve isolates as representatives of a single new species within the genus Sporosarcina, for which the name Sporosarcina newyorkensis sp. nov. (type strain 6062(T)  = DSM 23544(T)  = CCUG 59649(T)  = LMG 26022(T)) is proposed.