Glycyl Radical Enzymes and Sulfonate Metabolism in the Microbiome.

Sulfonates include diverse natural products and anthropogenic chemicals and are widespread in the environment. Many bacteria can degrade sulfonates and obtain sulfur, carbon, and energy for growth, playing important roles in the biogeochemical sulfur cycle. Cleavage of the inert sulfonate C-S bond involves a variety of enzymes, cofactors, and oxygen-dependent and oxygen-independent catalytic mechanisms. Sulfonate degradation by strictly anaerobic bacteria was recently found to involve C-S bond cleavage through O2-sensitive free radical chemistry, catalyzed by glycyl radical enzymes (GREs). The associated discoveries of new enzymes and metabolic pathways for sulfonate metabolism in diverse anaerobic bacteria have enriched our understanding of sulfonate chemistry in the anaerobic biosphere. An anaerobic environment of particular interest is the human gut microbiome, where sulfonate degradation by sulfate- and sulfite-reducing bacteria (SSRB) produces H2S, a process linked to certain chronic diseases and conditions.

Bacterial cysteate dissimilatory pathway involves a racemase and d-cysteate sulfo-lyase.

The sulfite-reducing bacterium Bilophila wadsworthia, a common human intestinal pathobiont, is unique in its ability to metabolize a wide variety of sulfonates to generate sulfite as a terminal electron acceptor (TEA). The resulting formation of H2S is implicated in inflammation and colon cancer. l-cysteate, an oxidation product of l-cysteine, is among the sulfonates metabolized by B. wadsworthia, although the enzymes involved remain unknown. Here we report a pathway for l-cysteate dissimilation in B. wadsworthia RZATAU, involving isomerization of l-cysteate to d-cysteate by a cysteate racemase (BwCuyB), followed by cleavage into pyruvate, ammonia and sulfite by a d-cysteate sulfo-lyase (BwCuyA). The strong selectivity of BwCuyA for d-cysteate over l-cysteate was rationalized by protein structural modeling. A homolog of BwCuyA in the marine bacterium Silicibacter pomeroyi (SpCuyA) was previously reported to be a l-cysteate sulfo-lyase, but our experiments confirm that SpCuyA too displays a strong selectivity for d-cysteate. Growth of B. wadsworthia with cysteate as the electron acceptor is accompanied by production of H2S and induction of BwCuyA. Close homologs of BwCuyA and BwCuyB are present in diverse bacteria, including many sulfate- and sulfite-reducing bacteria, suggesting their involvement in cysteate degradation in different biological environments.

Isethionate is an intermediate in the degradation of sulfoacetate by the human gut pathobiont Bilophila wadsworthia.

The obligately anaerobic sulfite-reducing bacterium Bilophila wadsworthia is a common human pathobiont inhabiting the distal intestinal tract. It has a unique ability to utilize a diverse range of food- and host-derived sulfonates to generate sulfite as a terminal electron acceptor (TEA) for anaerobic respiration, converting the sulfonate sulfur to H2S, implicated in inflammatory conditions and colon cancer. The biochemical pathways involved in the metabolism of the C2 sulfonates isethionate and taurine by B. wadsworthia were recently reported. However, its mechanism for metabolizing sulfoacetate, another prevalent C2 sulfonate, remained unknown. Here, we report bioinformatics investigations and in vitro biochemical assays that uncover the molecular basis for the utilization of sulfoacetate as a source of TEA (STEA) for B. wadsworthia, involving conversion to sulfoacetyl-CoA by an ADP-forming sulfoacetate-CoA ligase (SauCD), and stepwise reduction to isethionate by NAD(P)H-dependent enzymes sulfoacetaldehyde dehydrogenase (SauS) and sulfoacetaldehyde reductase (TauF). Isethionate is then cleaved by the O2-sensitive isethionate sulfolyase (IseG), releasing sulfite for dissimilatory reduction to H2S. Sulfoacetate in different environments originates from anthropogenic sources such as detergents, and natural sources such as bacterial metabolism of the highly abundant organosulfonates sulfoquinovose and taurine. Identification of enzymes for anaerobic degradation of this relatively inert and electron-deficient C2 sulfonate provides further insights into sulfur recycling in the anaerobic biosphere, including the human gut microbiome.

Discovery, characterization, and engineering of an advantageous Streptomyces host for heterologous expression of natural product biosynthetic gene clusters.

BACKGROUND: Streptomyces is renowned for its robust biosynthetic capacity in producing medically relevant natural products. However, the majority of natural products biosynthetic gene clusters (BGCs) either yield low amounts of natural products or remain cryptic under standard laboratory conditions. Various heterologous production hosts have been engineered to address these challenges, and yet the successful activation of BGCs has still been limited. In our search for a valuable addition to the heterologous host panel, we identified the strain Streptomyces sp. A4420, which exhibited rapid initial growth and a high metabolic capacity, prompting further exploration of its potential. RESULTS: We engineered a polyketide-focused chassis strain based on Streptomyces sp. A4420 (CH strain) by deleting 9 native polyketide BGCs. The resulting metabolically simplified organism exhibited consistent sporulation and growth, surpassing the performance of most existing Streptomyces based chassis strains in standard liquid growth media. Four distinct polyketide BGCs were chosen and expressed in various heterologous hosts, including the Streptomyces sp. A4420 wild-type and CH strains, alongside Streptomyces coelicolor M1152, Streptomyces lividans TK24, Streptomyces albus J1074, and Streptomyces venezuelae NRRL B-65442. Remarkably, only the Streptomyces sp. A4420 CH strain demonstrated the capability to produce all metabolites under every condition outperforming its parental strain and other tested organisms. To enhance visualization and comparison of the tested strains, we developed a matrix-like analysis involving 15 parameters. This comprehensive analysis unequivocally illustrated the significant potential of the new strain to become a popular heterologous host. CONCLUSION: Our engineered Streptomyces sp. A4420 CH strain exhibits promising attributes for the heterologous expression of natural products with a focus on polyketides, offering an alternative choice in the arsenal of heterologous production strains. As genomics and cloning strategies progress, establishment of a diverse panel of heterologous production hosts will be crucial for expediting the discovery and production of medically relevant natural products derived from Streptomyces.

Defective UiO-66-NH2 (Zr) for Simultaneous Adsorption of Phosphate and Pb2+ for Hydrogen Peroxide Purification.

Removal of hetero ions from the hydrogen peroxide solution is a crucial step in purifying electronic-grade H2O2. Conventional adsorption materials are challenged to meet the need for the simultaneous adsorption of both anions and cations in solvents. UiO-66 (Zr) modified by acetic acid and amino group for simultaneous adsorption of phosphate and Pb2+ in H2O2 purification was fabricated in this work. The as-prepared defective UiO-66-NH2 (Zr) demonstrated a significant increase in specific surface area and porosity, along with more exposed sites for phosphate and Pb2+ adsorption. The adsorption capacity of De-UiO-66-NH2 for phosphate and Pb2+ in H2O2 solution was 52.28 mg g-1 and 35.4 mg g-1, which is 1.19 times and 1.88 times that of unmodified UiO-66 (Zr), respectively. The trace simultaneous adsorption with both 100 ppb phosphate and Pb2+ showed removal rates of 94.0% and 88.7%, respectively, confirming the practicality of MOF materials in the purification of electronic chemicals. This work highlights the potential of Zr-based MOFs as anionic and cationic simultaneous adsorbents for highly efficient purification of electronic-grade solvents.

Biochemical investigations of polyphenol degradation enzymes in the phototrophic bacterium Rubrivivax gelatinosus.

Phloroglucinol (1,3,5-trihydroxybenzene) is an important intermediate in the degradation of flavonoids and tannins by anaerobic bacteria. Recent studies have shed light on the enzymatic mechanism of phloroglucinol degradation in butyrate-forming anaerobic bacteria, including environmental and intestinal bacteria such as Clostridium and Flavonifractor sp. Phloroglucinol degradation gene clusters have also been identified in other metabolically diverse bacteria, although the polyphenol metabolism of these microorganisms remain largely unexplored. Here, we describe biochemical studies of polyphenol degradation enzymes found in the purple non-sulfur bacterium Rubrivivax gelatinosus IL144, an anaerobic photoheterotroph reported to utilize diverse organic compounds as carbon sources for growth. In addition to the phloroglucinol reductase and dihydrophloroglucinol cyclohydrolase that catalyze phloroglucinol degradation, we characterize a Mn2+-dependent phloretin hydrolase that catalyzes the cleavage of phloretin into phloroglucinol and phloretic acid. We also report a Mn2+-dependent decarboxylase (DeC) that catalyzes the reversible decarboxylation of 2,4,6-trihydroxybenzoate to form phloroglucinol. A bioinformatics search led to the identification of DeC homologs in diverse soil and gut bacteria, and biochemical studies of a DeC homolog from the human gut bacterium Flavonifractor plautii demonstrated that it is also a 2,4,6-trihydroxybenzoate decarboxylase. Our study expands the range of enzymatic mechanisms for phloroglucinol formation, and provides further biochemical insight into polyphenol metabolism in the anaerobic biosphere.

A (S)-3-Hydroxybutyrate Dehydrogenase Belonging to the 3-Hydroxyacyl-CoA Dehydrogenase Family Facilitates Hydroxyacid Degradation in Anaerobic Bacteria.

Ketone bodies, including acetoacetate, 3-hydroxybutyrate, and acetone, are produced in the liver of animals during glucose starvation. Enzymes for the metabolism of (R)-3-hydroxybutyrate have been extensively studied, but little is known about the metabolism of its enantiomer (S)-3-hydroxybutyrate. Here, we report the characterization of a novel pathway for the degradation of (S)-3-hydroxybutyrate in anaerobic bacteria. We identify and characterize a stereospecific (S)-3-hydroxylbutyrate dehydrogenase (3SHBDH) from Desulfotomaculum ruminis, which catalyzes the reversible NAD(P)H-dependent reduction of acetoacetate to form (S)-3-hydroxybutyrate. 3SHBDH also catalyzes oxidation of d-threonine (2R, 3S) and l-allo-threonine (2S, 3S), consistent with its specificity for ß-(3S)-hydroxy acids. Isothermal calorimetry experiments support a sequential mechanism involving binding of NADH prior to (S)-3-hydroxybutyrate. Homologs of 3SHBDH are present in anaerobic fermenting and sulfite-reducing bacteria, and experiments with Clostridium pasteurianum showed that 3SHBDH, acetate CoA-transferase (YdiF), and (S)-3-hydroxybutyryl-CoA dehydrogenase (Hbd) are involved together in the degradation of (S)-3-hydroxybutyrate as a carbon and energy source for growth. (S)-3-hydroxybutyrate is a human metabolic marker and a chiral precursor for chemical synthesis, suggesting potential applications of 3SHBDH in diagnostics or the chemicals industry. IMPORTANCE (R)-3-hydroxybutyrate is well studied as a component of ketone bodies produced by the liver and of bacterial polyesters. However, the biochemistry of its enantiomer (S)-3-hydroxybutyrate is poorly understood. This study describes the identification and characterization of a stereospecific (S)-3-hydroxylbutyrate dehydrogenase and its function in a metabolic pathway for the degradation of (S)-3-hydroxybutyrate as a carbon and energy source in anaerobic bacteria. (S)-3-hydroxybutyrate is a mammalian metabolic marker and a precursor for chemical synthesis and bioplastics, suggesting potential applications of these enzymes in diagnostics and biotechnology.

A Variant of the Sulfoglycolytic Transketolase Pathway for the Degradation of Sulfoquinovose into Sulfoacetate.

Sulfoquinovose (SQ, 6-deoxy-6-sulfo-glucose) constitutes the polar head group of plant sulfolipids and is one of the most abundantly produced organosulfur compounds in nature. Degradation of SQ by bacterial communities contributes to sulfur recycling in many environments. Bacteria have evolved at least four mechanisms for glycolytic degradation of SQ, termed sulfoglycolysis, producing C3 sulfonate (dihydroxypropanesulfonate and sulfolactate) and C2 sulfonate (isethionate) by-products. These sulfonates are further degraded by other bacteria, leading to the mineralization of the sulfonate sulfur. The C2 sulfonate sulfoacetate is widespread in the environment and is also thought to be a product of sulfoglycolysis, although the mechanistic details are yet unknown. Here, we describe a gene cluster in an Acholeplasma sp., from a metagenome derived from deeply circulating subsurface aquifer fluids (GenBank accession no. QZKD01000037), encoding a variant of the recently discovered sulfoglycolytic transketolase (sulfo-TK) pathway that produces sulfoacetate instead of isethionate as a by-product. We report the biochemical characterization of a coenzyme A (CoA)-acylating sulfoacetaldehyde dehydrogenase (SqwD) and an ADP-forming sulfoacetate-CoA ligase (SqwKL), which collectively catalyze the oxidation of the transketolase product sulfoacetaldehyde into sulfoacetate, coupled with ATP formation. A bioinformatics study revealed the presence of this sulfo-TK variant in phylogenetically diverse bacteria, adding to the variety of mechanisms by which bacteria metabolize this ubiquitous sulfo-sugar. IMPORTANCE Many bacteria utilize environmentally widespread C2 sulfonate sulfoacetate as a sulfur source, and the disease-linked human gut sulfate- and sulfite-reducing bacteria can use it as a terminal electron receptor for anaerobic respiration generating toxic H2S. However, the mechanism of sulfoacetate formation is unknown, although it has been proposed that sulfoacetate originates from bacterial degradation of sulfoquinovose (SQ), the polar head group of sulfolipids present in all green plants. Here, we describe a variant of the recently discovered sulfoglycolytic transketolase (sulfo-TK) pathway. Unlike the regular sulfo-TK pathway that produces isethionate, our biochemical assays with recombinant proteins demonstrated that a CoA-acylating sulfoacetaldehyde dehydrogenase (SqwD) and an ADP-forming sulfoacetate-CoA ligase (SqwKL) in this variant pathway collectively catalyze the oxidation of the transketolase product sulfoacetaldehyde into sulfoacetate, coupled with ATP formation. A bioinformatics study revealed the presence of this sulfo-TK variant in phylogenetically diverse bacteria and interpreted the widespread existence of sulfoacetate.

Two radical-dependent mechanisms for anaerobic degradation of the globally abundant organosulfur compound dihydroxypropanesulfonate.

2(S)-dihydroxypropanesulfonate (DHPS) is a microbial degradation product of 6-deoxy-6-sulfo-d-glucopyranose (sulfoquinovose), a component of plant sulfolipid with an estimated annual production of 1010 tons. DHPS is also at millimolar levels in highly abundant marine phytoplankton. Its degradation and sulfur recycling by microbes, thus, play important roles in the biogeochemical sulfur cycle. However, DHPS degradative pathways in the anaerobic biosphere are not well understood. Here, we report the discovery and characterization of two O2-sensitive glycyl radical enzymes that use distinct mechanisms for DHPS degradation. DHPS-sulfolyase (HpsG) in sulfate- and sulfite-reducing bacteria catalyzes C-S cleavage to release sulfite for use as a terminal electron acceptor in respiration, producing H2S. DHPS-dehydratase (HpfG), in fermenting bacteria, catalyzes C-O cleavage to generate 3-sulfopropionaldehyde, subsequently reduced by the NADH-dependent sulfopropionaldehyde reductase (HpfD). Both enzymes are present in bacteria from diverse environments including human gut, suggesting the contribution of enzymatic radical chemistry to sulfur flux in various anaerobic niches.

Feasibility and self-perceived effectiveness of an online training program on dysphagia in residential aged care homes in mainland China.

BACKGROUND: With a rapidly aging population in mainland China, dysphagia has become one of the common geriatric disorders which creates a huge demand on speech and language therapists (SLTs). The major challenge is the shortage of SLTs in China. In addition, frontline practitioners in mainland China may not be well equipped with the knowledge and practical skills in dysphagia management due to lack of systematic training and the work nature. AIMS: This study evaluates the self-perceived effectiveness and feasibility of an online training program that aims to enhance the self-assessed knowledge and skills of SLTs providing dysphagia care in residential aged care homes. METHODS AND PROCEDURES: Sixteen SLTs working in a residential aged care homes in mainland China attended a three-hour pilot online training program which consists of didactic lecture and practical skills activity components. A total of 10 participants completed an online questionnaire one month after the training to evaluate the feasibility and effectiveness of this online training program. OUTCOMES AND RESULTS: The preliminary results demonstrated participants' self-perception of high training effectiveness in theoretical knowledge and practical skills. A majority of the participants perceived that the training enhanced their theoretical knowledge and all of them perceived that they acquired practical skills. All respondents were satisfied with the online training approach. They also highlighted the advantage and challenges of the online training approach. CONCLUSIONS AND IMPLICATIONS: Online training is an effective and feasible approach for theoretical knowledge and practical skills transfer in SLT training and could ultimately benefit the delivery of services for individuals with dysphagia in mainland China. WHAT THIS PAPER ADDS: What is already known on the subject Previous studies have shown that online training approach is as effective as face-to-face training in increasing professional knowledge. Online training programs may be more cost efficient and time efficient when compared with face-to-face training. What this study adds The present study provided preliminary evidence to support the feasibility and effectiveness of using online training on dysphagia for speech and language therapists working in residential aged care homes in mainland China. What are the clinical implications of this work? From the participants' perception, online training approach is effective and feasible in delivering theoretical knowledge and practical skills. It may be a better training approach for mainland China considering the lack of expertise and accessibility to training.

Long-term impact of a mental health literacy resource applied by regular classroom teachers in a Canadian school cohort.

Application of evidence-based mental health literacy (MHL) curriculum resources by classroom teachers has been demonstrated to significantly improve knowledge and decrease stigma in the short term. AIMS: To report results that extend these positive findings for a period of one year. METHOD: In a naturalistic cohort study, 332 grade 9 students (ages 14-15) in a Canadian school district learned from an evidence-based curriculum resource (the Guide) applied by classroom teachers who trained in its use. Evaluations of knowledge and stigma were conducted before the Guide, immediately following the Guide delivery and at one-year follow-up. RESULTS: Students showed significant (p < .001) and substantial (d = 0.68 and 0.67) short-term and significant (p < .001) and substantial (d = 0.44 and 0.58) long-term improvements in knowledge and reductions in stigma. Significant stigma reduction was found among female students than male students, but no gender differences on knowledge were found at long-term follow-up. Educators showed significant and substantial short-term improvements in knowledge (p < .001; d = 1.03) and reductions in stigma (p < .05; d = 0.35). CONCLUSIONS: The Guide resource delivered by trained classroom teachers may have value in enhancing MHL outcomes for young people.

Identification and Characterization of the Biosynthetic Pathway of the Sulfonolipid Capnine.

Capnine (2-amino-3-hydroxy-15-methylhexadecane-1-sulfonate) and capnoids (N-fatty acylated capnine derivatives) are sulfonolipids present in the outer membrane of gliding bacteria in the phylum Bacteroidetes and play a role in their unique gliding motility. They are structurally similar to sphingolipids and are thought to be biosynthesized via a similar pathway. Here we report the identification and biochemical characterization of the capnine biosynthetic enzymes cysteate synthase (CapA) and cysteate-C-fatty acyltransferase (CapB) from the pathogenic gliding bacterium Capnocytophaga ochracea and NAD(P)H-dependent dehydrocapnine reductase CapC from the avian pathogen Ornithobacterium rhinotracheale. CapA catalyzes the formation of cysteate from O-phospho-l-serine and sulfite, and CapB catalyzes the formation of dehydrocapnine from cysteate and 13-methyl-myristoyl-CoA, followed by reduction by CapC. CapA is closely related to cystathionine-ß-synthase but distantly related to the archaeal cysteate synthase. Close homologues of CapA, CapB, and the CapA isozyme archaeal cysteate synthase are present in many Bacteroidetes bacteria, including environmental, pathogenic, and human oral and intestinal microbiome bacteria, suggesting the widespread ability of these bacteria to biosynthesize capnine and related sulfonolipids.

Anaerobic Hydroxyproline Degradation Involving C-N Cleavage by a Glycyl Radical Enzyme.

Hydroxyprolines are highly abundant in nature as they are components of many structural proteins and osmolytes. Anaerobic degradation of trans-4-hydroxy-l-proline (t4L-HP) was previously found to involve the glycyl radical enzyme (GRE) t4L-HP dehydratase (HypD). Here, we report a pathway for anaerobic hydroxyproline degradation that involves a new GRE, trans-4-hydroxy-d-proline (t4D-HP) C-N-lyase (HplG). In this pathway, cis-4-hydroxy-l-proline (c4L-HP) is first isomerized to t4D-HP, followed by radical-mediated ring opening by HplG to give 2-amino-4-ketopentanoate (AKP), the first example of a ring opening reaction catalyzed by a GRE 1,2-eliminase. Subsequent cleavage by AKP thiolase (OrtAB) yields acetyl-CoA and d-alanine. We report a crystal structure of HplG in complex with t4D-HP at a resolution of 2.7 Å, providing insights into its catalytic mechanism. Different from HypD commonly identified in proline-reducing Clostridia, HplG is present in other types of fermenting bacteria, including propionate-producing bacteria, underscoring the diversity of enzymatic radical chemistry in the anaerobic microbiome.

Enzymatic Synthesis of the Unnatural Nucleotide 2'-Deoxyisoguanosine 5'-Monophosphate.

Naturally occurring DNA contains four canonical bases, forming two Watson-Crick base pairs (adenine-thymine, guanine-cytosine). Efforts over the past decades have led to the development of several unnatural base pairs, enabling the synthesis of unnatural DNA with an expanded genetic alphabet. The engineering of organisms capable of de novo biosynthesis of unnatural DNA would have significant technological and philosophical implications, but remains a challenge. Here we report the enzymatic conversion of 2'-deoxyxanthosine 5'-monophosphate (dXMP) into deoxyisoguanosine monophosphate (dBMP), a precursor of the unnatural isoguanine-isocytosine base pair. The reaction is catalyzed by the bacteriophage enzyme PurZ and bacterial PurB, and is a key addition to the toolbox for de novo biosynthesis of unnatural DNA.

The Impact of Transitions, a Mental Health Literacy Intervention With Embedded Life Skills for Postsecondary Students: Preliminary Findings From a Naturalistic Cohort Study.

OBJECTIVE: Mental illness is a common medical condition to onset during adolescence. Young people who leave for postsecondary life are at an especially challenging period of lifetime when many will leave home and familiar environments for prolonged periods of time. These new circumstances may put young people at risk of developing mental health problems or disorders or exacerbate existing mental disorders. Alternatively, some young people may misinterpret the normal negative emotional states occurring as a result of these new challenges as a mental disorder requiring professional intervention. We conducted a quasiexperimental cohort study to investigate the effectiveness of a mental health literacy intervention Transitions with blended life skills to address these challenges for first-year postsecondary students. METHODS: Students (n = 2,397) from five Canadian postsecondary institutions were assigned to the intervention or the control group and were administered a survey at baseline, postintervention, and at 2-month follow-up (September 2017 to February 2018). We applied generalized linear mixed effects (PROC Mixed procedure) to test the between-group difference in the post-pre/follow-up-pre and to determine the predicted least-square mean values. RESULTS: The findings showed that students who were exposed to the Transitions intervention significantly improved their mental health knowledge, decreased stigma against mental illness, improved help-seeking attitudes and behaviours, and decreased perceived stress when compared to students who had not been exposed to the intervention. However, we did not identify significant changes in general health. This may be due to the relatively short follow-up time (2 months) to determine participants' general health status. CONCLUSIONS: Transitions delivered to first-year postsecondary students may be a beneficial intervention to help young people adjust to their new postsecondary life and improve their mental health.

Five year cost savings of a multimodal treatment program for child sexual abuse (CSA): a social return on investment study.

BACKGROUND: Specialized mental health services for the treatment of Child Sexual Abuse (CSA) are generally expensive and labour intensive. They require a trauma-informed approach that may involve multiple services and therapeutic modalities, provided over the course of several months. That said, given the broad-ranging, long term negative sequelae of CSA, an evaluation of the cost-benefit analysis of treatment is clearly justified. METHODS: We performed a Social Return on Investment (SROI) analysis of data gathered as part of the treatment program at the Be Brave Ranch in Edmonton, Canada to determine the value-for-money of the services provided. We endeavoured to take a conservative, medium-term (5 year) perspective; this is in contrast to short term (1-2 year) effects, which may rapidly dissipate, or long term (15-20 year) effects, which are likely diffuse and difficult to measure. As such, our analysis was based on an average annual intake of 100 children/adolescents (60:40 split) and their families, followed over a five-year timeframe. Financial proxies were assigned to benefits not easily monetized, and six potential domains of cost savings were identified. RESULTS: Our analyses suggest that each dollar spent in treatment results in an average cost savings of $11.60 (sensitivity analysis suggests range of 9.20-12.80). The largest value-for-money was identified as the domain of crisis prevention, via the avoidance of rare but costly events associated with the long term impacts of CSA. Somewhat surprisingly, savings related to the area of criminal justice were minimal, compared to other social domains analysed. Implications are discussed. CONCLUSIONS: Our results support the cost effectiveness of the investment associated with specialized, evidence-based early interventions for CSA. These approaches alleviate severe, negative outcomes associated with CSA, resulting in both economic savings and social benefits. These findings rest upon a number of assumptions, and generalizability of these results is therefore limited to similar programs located in comparable areas. However, the SROI ratio achieved in this analysis, in excess of $11:1, supports the idea that, while costly, these services more than pay for themselves over time.

Biochemical Investigation of 3-Sulfopropionaldehyde Reductase HpfD.

Sulfoquinovose is the polar headgroup of plant sulfolipids and is a globally abundant organosulfur compound, and its degradation by bacteria is an important component of the sulfur cycle. Sulfoquinovose degradation by certain bacteria, including Escherichia coli, produces dihydroxypropanesulfonate (DHPS), which is further converted by anaerobic bacteria into 3-hydroxypropanesulfonate (3-HPS), through the catalytic action of DHPS dehydratase (a member of the glycyl radical enzyme family), and sulfopropionaldehyde reductase HpfD (a member of the metal-dependent alcohol dehydrogenase family). Here we report biochemical investigation of Hungatella hathewayi HpfD. In addition to 3-HPS, HpfD also displayed high catalytic activities for NAD+ -dependent oxidation of 4-hydroxybutanesulfonate (4-HBS) and γ-hydroxybutyrate (GHB). The highest activity was obtained with Fe2+ or Mn2+ as the divalent metal cofactor. Bioinformatics studies suggest that, in addition to DHPS degradation, 3-HPS and γ-aminobutyrate (GABA) degradations also involve HpfD homologs.

Digital mental health literacy -program for the first-year medical students' wellbeing: a one group quasi-experimental study.

BACKGROUND: Medical students are prone to mental disorders, such as depression and anxiety, and their psychological burden is mainly related to their highly demanding studies. Interventions are needed to improve medical students' mental health literacy (MHL) and wellbeing. This study assessed the digital Transitions, a MHL program for medical students that covered blended life skills and mindfulness activities. METHODOLOGY: This was a one group, quasi-experimental pretest-posttest study. The study population was 374 first-year students who started attending the medical faculty at the University of Turku, Finland, in 2018-2019. Transitions was provided as an elective course and 220 students chose to attend and 182 agreed to participate in our research. Transitions included two 60-minute lectures, four weeks apart, with online self-learning material in between. The content focused on life and academic skills, stress management, positive mental health, mental health problems and disorders. It included mindfulness audiotapes. Mental health knowledge, stigma and help-seeking questionnaires were used to measure MHL. The Perceived Stress Scale and General Health Questionnaire measured the students' stress and health, respectively. A single group design, with repeated measurements of analysis of variance, was used to analyze the differences in the mean outcome scores for the 158 students who completed all three stages: the pre-test (before the first lecture), the post-test (after the second lecture) and the two-month follow-up evaluation. RESULTS: The students' mean scores for mental health knowledge improved (-1.6, 95% Cl -1.9 to -1.3, P<.001) and their emotional symptoms were alleviated immediately after the program (0.5, 95% Cl 0.0 to 1.1, P=.040). The changes were maintained at the two-month follow up (-1.7, 95% Cl -2.0 to -1.4, P<.001 and 1.0, 95% Cl 0.2 to 1.8, P=.019, respectively). The students' stress levels reduced (P=.022) and their attitudes towards help-seeking improved after the program (P<.001), but these changes were not maintained at the two-month follow up. The stigma of mental illness did not change during the study (P=.13). CONCLUSIONS: The digital Transitions program was easily integrated into the university curriculum and it improved the students' mental health literacy and wellbeing. The program may respond to the increasing global need for universal digital services, especially during the lockdowns due to the COVID-19 pandemic. TRIAL REGISTRATION: The trial was registered at the ISRCTN registry (26 May 2021), registration number 10.1186/ ISRCTN10565335 ).

An extended bacterial reductive pyrimidine degradation pathway that enables nitrogen release from ß-alanine.

The reductive pyrimidine catabolic pathway is the most widespread pathway for pyrimidine degradation in bacteria, enabling assimilation of nitrogen for growth. This pathway, which has been studied in several bacteria including Escherichia coli B, releases only one utilizable nitrogen atom from each molecule of uracil, whereas the other nitrogen atom remains trapped in the end product ß-alanine. Here, we report the biochemical characterization of a ß-alanine:2-oxoglutarate aminotransferase (PydD) and an NAD(P)H-dependent malonic semialdehyde reductase (PydE) from a pyrimidine degradation gene cluster in the bacterium Lysinibacillus massiliensis Together, these two enzymes converted ß-alanine into 3-hydroxypropionate (3-HP) and generated glutamate, thereby making the second nitrogen from the pyrimidine ring available for assimilation. Using bioinformatics analyses, we found that PydDE homologs are associated with reductive pyrimidine pathway genes in many Gram-positive bacteria in the classes Bacilli and Clostridia. We demonstrate that Bacillus smithii grows in a defined medium with uracil or uridine as its sole nitrogen source and detected the accumulation of 3-HP as a waste product. Our findings extend the reductive pyrimidine catabolic pathway and expand the diversity of enzymes involved in bacterial pyrimidine degradation.

A transaldolase-dependent sulfoglycolysis pathway in Bacillus megaterium DSM 1804.

Sulfoquinovose (6-deoxy-6-sulfoglucose, SQ) is a component of sulfolipids found in the photosynthetic membranes of plants and other photosynthetic organisms, and is one of the most abundant organosulfur compounds in nature. Microbial degradation of SQ, termed sulfoglycolysis, constitutes an important component of the biogeochemical sulfur cycle. Two sulfoglycolysis pathways have been reported, with one resembling the Embden-Meyerhof-Parnas (sulfo-EMP) pathway, and the other resembling the Entner-Doudoroff (sulfo-ED) pathway. Here we report a third sulfoglycolysis pathway in the bacterium Bacillus megaterium DSM 1804, in which sulfosugar cleavage is catalyzed by the transaldolase SqvA, which converts 6-deoxy-6-sulfofructose and glyceraldehyde 3-phosphate into fructose -6-phosphate and (S)-sulfolactaldehyde. Variations of this transaldolase-dependent sulfoglycolysis (sulfo-TAL) pathway are present in diverse bacteria, and add to the diversity of mechanisms for the degradation of this abundant organosulfur compound.