Sulfate-reducing bioreactors subjected to high sulfate loading rate or acidity: variations in microbial consortia.

Sulfate-reducing bioreactors are used in e.g. the mining industry to remove sulfate and harmful metals from process waters. These bioreactors are expected to be run for extended periods of time and may experience variations in the influent quality, such as increasing sulfate loading rate and decrease in pH, while being expected to function optimally. In this study we followed the sulfate removal rate and variation in microbial communities over a period of up to 333 days in three different up-flow anaerobic sludge blanket (UASB) bioreactors being submitted to increasing sulfate loading rate or decreasing pH. Sodium lactate was used as the sole carbon source and electron donor. All three bioreactors contained highly diverse microbial communities containing archaea, fungi and bacteria. Sulfurospirillum and Desulfovibrio were the most prominent bacterial genera detected in the bioreactors receiving the highest sulfate loading rates, and the greatest relative abundance of methanogenic archaea and the fungal genus Cadophora coincided with the highest sulfate reduction rates. In contrast, Sulfuricurvum was dominant in the bioreactor receiving influent with alternating pH, but its relative abundance receded in response to low pH of the influent. All bioreactors showed excellent sulfate removal even under extreme conditions in addition to unique responses in the microbial communities under changing operational conditions. This shows that a high diversity in the microbial consortia in the bioreactors could make the sulfate removal process less sensitive to changing operational conditions, such as variations in influent sulfate loading rate and pH.

Screening Mold Colonies by Using Two Toxicity Assays Revealed Indoor Strains of Aspergillus calidoustus Producing Ophiobolins G and K.

The occurrence and toxin production of the opportunistic pathogen Aspergillus calidoustus in Finnish buildings is not well documented in the literature. We tracked and identified four A. calidoustus colonies cultivated from indoor settled dusts and revealed the biological activities of crude biomass extracts. The toxic substances were identified as 6-epi-ophiobolin K, ophiobolin K, and ophiobolin G by high-performance liquid chromatography-mass spectrometry (HPLC-MS) based on chromatographic and mass spectrometry data (MS and MS/MS) on the crude extract of A. calidoustus strain MH34. A total of 29 fungal colonies collected from settled dust in an office room reported for indoor-air-related illnesses were screened for toxins that inhibited boar sperm motility in the BSMI (boar sperm motility inhibiting) assay and cell proliferation in the ICP (inhibition of cell proliferation) assays with PK-15 cells. Out of the 27 colonies tested as toxic, 12 colonies exhibiting conidiophores representative of the genera Chaetomium, Penicillium, and Paecilomyces were excluded from the study, while 13 colonies exhibited Aspergillus-like conidiophores. Biomass suspensions of these colonies were divided into two categories: Category 1 colonies (n = 4), toxic in the BSMI assay and the ICP assays, emitted blue fluorescence and grew at 37 °C; Category 2 colonies (n = 9), only toxic in the ICP assay, emitted orange fluorescence and exhibited limited or no growth at 37 °C. Colonies in Category 1 were pure-cultured, and the strains were named as MH4, MH21, MH34, MH36. Strain MH34 was identified as A. calidoustus by the internal transcribed spacer (ITS) sequences. Ethanol-soluble dry substances extracted from the biomass of the pure cultures exhibited a toxicological profile in the BSMI assay, SMID (sperm membrane integrity damage) assay, and ICP assay similar to that exhibited by pure ophiobolin A. Overall, the viable conidia of A. calidoustus in indoor settled dusts deserve attention when potentially hazardous mold species are monitored.

Microbial Community Structure and Functions in Ethanol-Fed Sulfate Removal Bioreactors for Treatment of Mine Water.

Sulfate-rich mine water must be treated before it is released into natural water bodies. We tested ethanol as substrate in bioreactors designed for biological sulfate removal from mine water containing up to 9 g L-1 sulfate, using granular sludge from an industrial waste water treatment plant as inoculum. The pH, redox potential, and sulfate and sulfide concentrations were measured twice a week over a maximum of 171 days. The microbial communities in the bioreactors were characterized by qPCR and high throughput amplicon sequencing. The pH in the bioreactors fluctuated between 5.0 and 7.7 with the highest amount of up to 50% sulfate removed measured around pH 6. Dissimilatory sulfate reducing bacteria (SRB) constituted only between 1% and 15% of the bacterial communities. Predicted bacterial metagenomes indicated a high prevalence of assimilatory sulfate reduction proceeding to formation of l-cystein and acetate, assimilatory and dissimilatory nitrate reduction, denitrification, and oxidation of ethanol to acetaldehyde with further conversion to ethanolamine, but not to acetate. Despite efforts to maintain optimal conditions for biological sulfate reduction in the bioreactors, only a small part of the microorganisms were SRB. The microbial communities were highly diverse, containing bacteria, archaea, and fungi, all of which affected the overall microbial processes in the bioreactors. While it is important to monitor specific physicochemical parameters in bioreactors, molecular assessment of the microbial communities may serve as a tool to identify biological factors affecting bioreactor functions and to optimize physicochemical attributes for ideal bioreactor performance.

Botulinum toxin type A injections into the calf muscles for treatment of spastic equinus in cerebral palsy: a randomized trial comparing single and multiple injection sites.

OBJECTIVE: To investigate the hypothesis that the multiple-site injection technique is associated with better outcomes than the single-point injection method in children with cerebral palsy and spastic equinus gait. DESIGN: A total of 17 children (nine boys, eight girls ages 1.8-9.4 yrs; eight hemiplegics, eight diplegics, one quadriplegic; levels I-IV with the Gross Motor Function Classification System) with 25 treated lower limbs were randomized into two groups: a single-point group receiving a standard dose of botulinum toxin A injection into one site and a multiple-points group into two sites on both heads of the gastrocnemius. Active and passive range of movement, selective dorsiflexion, dynamic muscle length (modified Tardieu scale), calf tone (modified Ashworth scale), attainment of anticipated gait pattern (Goal Attainment Scale), and video gait analysis (Observational Gait Scale [OGS]) were assessed before and 1, 2, and 4 mos after intervention. RESULTS: Both groups improved in dynamic muscle length, muscle tone, OGS-total scores and initial foot contact scores and a similar number of children attained their goals on the Goal Attainment Scale. The only significant difference between the groups was observed at 2 mos in passive dorsiflexion with the knee flexed, favoring the single-point group. Though not significantly, the incidence of adverse effects was higher in the multiple-points group. CONCLUSIONS: Using the methods described, no major changes in main outcome measures were associated with the number of injection sites. Issues other than efficacy guide the decision on whether to inject in single or multiple sites when treating spastic equinus with botulinum toxin.

Botulinum toxin treatment of spastic equinus in cerebral palsy: a randomized trial comparing two injection sites.

OBJECTIVE: To explore the clinical relevance of injection site by comparing two different injection techniques in children with cerebral palsy who have spastic equinus gait. DESIGN: A total of 19 children (13 boys, 6 girls; range, 1 yr 6 mos to 7 yrs; nine hemiplegics, eight diplegics, two quadriplegics; levels I to IV with the Gross Motor Function Classification System) participated in the study. The children were randomized into two groups: the proximal group received a botulinum toxin A injection into the proximal part of both heads of the gastrocnemius, and the distal group received a botulinum toxin A injection into the mid-belly of the muscle bulks. A single-point injection of BOTOX, 3 units/kg per site, was used. Assessments of active and passive range of motion, dynamic muscle length (modified Tardieu scale), calf tone (modified Ashworth scale), and video gait analysis (Observational Gait Scale) were performed before treatment and 3, 8, and 16 wks posttreatment. RESULTS: Active and passive dorsiflexion and calf tone in both groups and Observational Gait Scale total scores in the distal group improved at all time points. The median change from baseline values in Observational Gait Scale initial foot contact and total scores at 8 wks showed a significant difference favoring the distal group, but the clinical relevance remained tenuous. CONCLUSIONS: Using the methods described, no major changes in main outcome measures were associated with changing the injection site.