Niche Competition Research Articles

Could the transcription factor AtnN coordinating the aspercryptin secondary metabolite gene cluster in Aspergillus nidulans be a global regulator?

Products of dormant secondary metabolite gene clusters of fungal genomes can be exploited for medical purposes as bioactive agents. These clusters can be switched on under oxidative stress and may endow fungi with a versatile chemical armory in a competitive niche. In Aspergillus nidulans, the aspercryptin gene cluster, including the synthase [atnA (AN7884)] and its transcription factor (atnN), was activated under menadione sodium bisulfite (MSB) treatment. In this study, we generated and phenotypically examined the gene deletion and overexpression mutants of atnN and studied the secondary metabolite production of the mutants. Overexpression of atnN significantly reduced the colony growth of surface cultures compared to the control. The ΔatnN gene deletion strain showed higher sensitivity to tert-butyl hydroperoxide (tBOOH), while the atnNOE strain was more resistant to MSB, Congo Red, and sorbitol. Interestingly, deletion of atnN decreased cleistothecia formation of A. nidulans. Manipulation of atnN affected the synthesis of several secondary metabolites, for example, the siderophore production of A. nidulans. The extracellular triacetylfusarinine C (TAFC) production decreased, while the intracellular ferricrocin (FC) concentration of the cultures increased in the atnNOE mutant cultivating A. nidulans in a complex medium containing 1% mycological peptone and 2% maltose. In Czapek-Dox Broth medium, increased asperthecin production was observed in the ΔatnN mutant. The mycotoxin sterigmatocystin synthesis elevated in the ΔatnN mutant, while reduced in the atnNOE mutant on minimal medium. Our study supports previous observations that secondary metabolite production is coordinated in a complex way, and the linkage of stress response, sexual reproduction, and secondary metabolite production can be governed by several transcription factors.

Taeniasis impacts human gut microbiome composition and function.

Human taeniasis, caused by Taenia tapeworms, is a global parasitic disease with significant implications for public health and food safety. These tapeworms can grow to considerable sizes and potentially impact the microecology of the host gut. Despite their importance, the effects of Taenia infection on host gut microbiota haven't been thoroughly investigated. In this study, we conducted a cross-sectional analysis of the gut microbiome in patients infected with Taenia asiatica (n = 87) compared to healthy controls (n = 79) in the Dali cohort, China. We also performed a longitudinal assessment of microbial changes following deworming in a subset of patients (n = 24). Our findings reveal a significant shift in gut microbial composition, characterized by increased alpha-diversity and an enrichment of Prevotella-driven enterotypes in infected patients compared to healthy controls. The stability of these microbial features post-deworming varied widely among individuals and was lower in those with lower initial alpha diversity and Prevotella-enterotype before deworming. We observed a significant depletion of Bifidobacterium species in infected individuals, regardless of enterotypes, and these prebiotics did not recover post-deworming. Metabolic network analysis and in vitro experiments suggest that the reduction of Bifidobacterium was linked to metabolic competition for ecological niches or nutrients, particularly stachyose, from other microbes rather than the parasitism itself. Furthermore, our machine learning analysis demonstrated that taxa associated with Bifidobacterium in stachyose metabolism could robustly predict infection but could not predict deworming. This study highlights the substantial impact of taeniasis on the human gut microbiome and overall gut health.

Solid tumour-induced systemic immunosuppression involves dichotomous myeloid-B cell interactions.

Solid tumours induce systemic immunosuppression that involves myeloid and T cells. B cell-related mechanisms remain relatively understudied. Here we discover two distinct patterns of tumour-induced B cell abnormality (TiBA; TiBA-1 and TiBA-2), both associated with abnormal myelopoiesis in the bone marrow. TiBA-1 probably results from the niche competition between pre-progenitor-B cells and myeloid progenitors, leading to a global reduction in downstream B cells. TiBA-2 is characterized by systemic accumulation of a unique early B cell population, driven by interaction with excessive neutrophils. Importantly, TiBA-2-associated early B cells foster the systemic accumulation of exhaustion-like T cells. Myeloid and B cells from the peripheral blood of patients with triple-negative breast cancer recapitulate the TiBA subtypes, and the distinct TiBA profile correlates with pathologic complete responses to standard-of-care immunotherapy. This study underscores the inter-patient diversity of tumour-induced systemic changes and emphasizes the need for treatments tailored to different B and myeloid cell abnormalities.

The bifunctional impact of polylactic acid microplastics on composting processes and soil-plant systems: Dynamics of microbial communities and ecological niche competition

Although extensive research has been conducted on the environmental impact of microplastics (MPs), their effects on microorganisms during the composting process and on the compost-soil system remain unclear. Our research investigates the microbial response to polylactic acid microplastics (PLAMPs) during aerobic composting and examines how compost enriched with PLAMPs affects plants. Our findings reveal that PLAMPs play a dual role in the composting process, influencing microorganisms differently depending on the composting phase. PLAMPs reduce the relative abundance of sensitive bacterial ASVs, specifically those belonging to Limnochordaceae and Enterobacteriaceae, during composting, while increasing the relative abundance of ASVs belonging to Steroidobacteriaceae and Bacillaceae. The impact of PLAMPs on microbial community assembly and niche width was found to be phase-dependent. In the stabilization phase (S5), the presence of PLAMPs caused a shift in the core microbial network from bacterial dominance to fungal dominance, accompanied by heightened microbial antagonism. Additionally, these intricate microbial interactions can be transferred to the soil ecosystem. Our study indicates that composting, as a method of managing PLAMPs, is also influenced by PLAMPs. This influence is transferred to the soil through the use of compost, resulting in severe oxidative stress in plants. Our research is pivotal for devising future strategies for PLAMPs management and predicting the subsequent changes in compost quality and environmental equilibrium.

Environmental factors associated with Oncomelania hupensis lindoensis snails in a schistosomiasis-endemic area in Napu, Central Sulawesi.

The presence of the freshwater snail Oncomelania hupensis lindoensis in their habitats is influenced by abiotic environmental factors (nutrients, water salinity, and predators) that play a crucial role in maintaining snail survival. The objective of this study is to determine the relationship between environmental factors and the presence of O. hupensis lindoensis snails in the Napu Valley, one of the Schistosomiasis-endemic areas in Indonesia. Eight environmental factors were measured in three different habitats: a seepage, a ditch, and a pond. The study found O. hupensis lindoensis snails in all three habitats, with significant differences in their numbers (p < 0.05). The seepage habitat had the highest snail density (762.22 snails per m2) compared to the other habitats. Phosphorus levels were highest in the seepage habitat compared to the other habitats, while nitrogen levels were highest in the pond habitat. Pearson correlation analysis found a significant positive correlation between O. hupensis lindoensis snails and water salinity in the ditch habitat (p < 0.05). In addition to environmental factors, the presence of snails can also be influenced by other factors, such as the presence of snail predators, the presence of snail nutrients, and the population of snail host niche competitors.

Competition for nutrient niches within the apple blossom microbiota antagonizes the initiation of fire blight infection.

Changes in the plant microbiota composition are intimately associated with the health of the plant, but factors controlling the microbial community in flowers are poorly understood. In this study, we used apple flowers and fire blight as a model system to investigate the effects of floral microbiota and microbial competition on disease development and suppression. To compare changes in microbial flora with the RNA expression patterns of plants, the flower samples were collected in three different flowering stages (Bud, Popcorn, and Full-bloom). Using advanced sequencing technology, we analyzed the data and conducted both in vitro and in vivo experiments to validate our findings. Our results show that the Erwinia amylovora use arabinogalactan, which is secreted on the flowers, for early colonization of apple flowers. Pantoea agglomerans was more competitive for arabinogalactan than E. amylovora. Additionally, P. agglomerans suppressed the expression of virulence factors of E. amylovora by using arabinose, which is a major component of arabinogalactan, which induces virulence gene expression. The present data provide new insights into developing control strategies for diverse plant diseases, including fire blight, by highlighting the importance of nutrients in disease development or suppression.

Past and current climate as a driver in shaping the distribution of the Longitarsus candidulus species group (Coleoptera: Chrysomelidae).

Longitarsus candidulus (Foudras) is a thermophilic flea beetle species widely distributed in the Mediterranean Basin and associated with Daphne gnidium L. and Thymelaea hirsuta (L.). Longitarsus laureolae Biondi and Longitarsus leonardii Doguet, phylogenetically closely related to L. candidulus, show together a peculiar and rare disjunct distribution along the central-southern Apennines and the Cantabrian-Pyrenean mountain system, respectively. Both are associated with Daphne laureola L. in mesophilic habitats. We used "ecological niche modeling" to infer the Pleistocene dynamics in the distribution of the three flea beetle species and their host plants. We interpreted their current distributions, paying particular attention to the presumed time of species divergence as inferred from recent studies. The differentiation of L. laureolae and L. leonardii from L. candidulus likely represents a response to the marked climatic changes during the Late Pliocene. Such a split was likely associated with a trophic niche shift of the laureolae/leonardii ancestor towards the typically mesophilic host plant D. laureola. The subsequent split between L. laureolae and L. leonardii, possibly due at first to the niche competition, was then boosted by an allopatric divergence during the Middle Pleistocene, likely caused by a large area of low environmental suitability for both species, mainly located between the northern Apennines and the south-western Alps.

A group B streptococcal type VII-secreted LXG toxin mediates interbacterial competition and colonization of the murine female genital tract.

Group B Streptococcus (GBS) asymptomatically colonizes the vagina but can opportunistically ascend to the uterus and be transmitted vertically during pregnancy, resulting in neonatal pneumonia, bacteremia, and meningitis. GBS is a leading etiologic agent of neonatal infection and understanding the mechanisms by which GBS persists within the polymicrobial female genital mucosa has the potential to mitigate subsequent transmission and disease. Type VIIb secretion systems (T7SSb) are encoded by Bacillota and often mediate interbacterial competition using LXG toxins that contain conserved N-termini important for secretion and variable C-terminal toxin domains that confer diverse biochemical activities. Our recent work characterized a role for the GBS T7SSb in vaginal colonization and ascending infection but the mechanisms by which the T7SSb promotes GBS persistence in this polymicrobial niche remain unknown. Herein, we investigate the GBS T7SS in interbacterial competition and GBS niche establishment in the female genital tract. We demonstrate GBS T7SS-dependent inhibition of mucosal pathobiont Enterococcus faecalis both in vitro using predator-prey assays and in vivo in the murine genital tract and found that a GBS LXG protein encoded within the T7SS locus (herein named group B streptococcal LXG Toxin A) contributes to these phenotypes. We identify BltA as a T7SS substrate that is toxic to E. coli and S. aureus upon induction of intracellular expression along with associated chaperones. Finally, we show that BltA and its chaperones contribute to GBS vaginal colonization. Altogether, these data reveal a role for a novel T7b-secreted toxin in GBS mucosal persistence and competition.IMPORTANCECompetition between neighboring, non-kin bacteria is essential for microbial niche establishment in mucosal environments. Gram-positive bacteria encoding T7SSb have been shown to engage in competition through the export of LXG-motif-containing toxins, but these have not been characterized in group B Streptococcus (GBS), an opportunistic colonizer of the polymicrobial female genital tract. Here, we show a role for GBS T7SS in competition with mucosal pathobiont Enterococcus faecalis, both in vitro and in vivo. We further find that a GBS LXG protein contributing to this antagonism is exported by the T7SS and is intracellularly toxic to other bacteria; therefore, we have named this protein group B streptococcal LXG Toxin A (BltA). Finally, we show that BltA and its associated chaperones promote persistence within female genital tract tissues, in vivo. These data reveal previously unrecognized mechanisms by which GBS may compete with other mucosal opportunistic pathogens to persist within the female genital tract.

Inbound social media marketing and increased sales in SMEs: a correlational study in the pet food industry

New market trends have prompted Peruvian companies to apply techniques aimed at attracting potential customers, that is, to use inbound marketing, especially in the pet market, which has a profitable and competitive niche, driven mainly by the “pet-friendly” trend. This research aims to determine whether inbound marketing actions have a positive correlation with online sales. The methodology is quantitative, correlation, cross-sectional, and non-experimental. The target audience is men and women, between 18 and 35 years old who have made online purchases in the Peruvian pet food SME, Rapi Pet S.R.L. The sample is non-probabilistic and is composed of 248 people who completed a structured questionnaire of 24 questions. The results show positive perceptions of both variables with values higher than 70% after applying the barometer test, the reliability of the questionnaire was also established under Cronbach’s alpha of 0.922 and a correlation coefficient of 0.66 was obtained for the variables, as well as a p-value lower than 0.05 after performing the normality test. It is concluded that there is a positive relationship between inbound marketing actions and the increase of online sales in the company under study.

Malaysia Meets (and Remains in) the Middle-Income Trap: Lost Coalition amidst Industrial Value Migration

Once an aspiring nation on the path towards achieving high-income status, Malaysia’s efforts to break its vicious cycle of low productivity-cum-low wage were hindered by ineffective attempts to form an upgrading coalition. The coalition not only failed to make material progress in addressing industrial needs, but also faced an increasingly isolationist international trade and investment climate where transnational corporations were encouraged to reshore/friendshore productive activities back to their home/like-minded economies. This paper analysed three structural reasons miring the nation in the middle-income trap. Firstly, the Malaysian economy was struggling to establish its competitive niche. This occurred as Malaysia grew increasingly reliant on extractive and service-based industries, while its labour-intensive activities struggled in adapting to the demands of Industry 4.0. Secondly, there was insufficient interest in promoting indigenous technologies and championing industrial upgrading. The statebusiness coalition primarily focused on highly regulated, non-tradable industries such as utility provision, banking and real estate. Finally, we observed a skills mismatch between the push for science and technology education and the labour market’s demand for general, undifferentiated skills to support low value-added operations. Unless these interrelated challenges are effectively addressed, the nation will likely experience frustration in breaking through the impasse.

No evidence for niche competition in the extinction of the South American saber-tooth species

The end of South American isolation during the Great American Biotic Interchange (GABI) promoted the contact between South and North American saber-tooth forms that evolved in isolation. This contact may have driven saber-tooth species to a competitive interaction, resulting in the extinction of the South American saber-tooth form. Here, we used paleoclimatic data to compare the climatic niche of the saber-tooth forms Thylacosmilus atrox (from South America), Smilodon fatalis, and Smilodon populator (both originally from North America). We evaluated niche width, overlap, and similarity to infer potential geographic distribution overlap and competition between these North and South American predators. To do so, we obtained the climatic variables from sites where occurrence fossil records were available. Our results suggest that T. atrox had a narrower climatic niche compared to Smilodon species. Although we found a significant climatic niche overlap and similarity between S. fatalis and T. atrox, it seems unlikely that both species have co-occurred. Low niche overlap and similarity between T. atrox and S. populator dismiss competitive interaction between them. Moreover, climatic niche and low tolerance for environmental changes may have been the cause of the South American saber-tooth extinction.

Influence of abiotic factors on the germination of an endemic sea lavender: First steps to shape local assemblage

Different Mediterranean sea lavender species, especially endemisms, appear within specific soil conditions led by vegetative trait syndromes. Nonetheless, seed traits contribute to functional structuring of plant communities, shaping the first stages of plant fitness and niche competition in stressful habitats. In this framework, we assess abiotic factors related to germination and establishment of Limonium tobarrense, an inland saltmarsh endemism located at the southeastern of the Iberian Peninsula, to shed light about the assembly processes in its early life stage. Experiments were performed to determine the effects of different salinities (0%, 0.5%, 1%, 1.5% and 2% NaCl) on seed germination under three combinations of day/night temperature (30 °C/20 °C, 25 °C/20 °C and 25 °C/15 °C) with a photoperiod of 12 h in light and 12 h in dark. Final germination percentage (FGP) and mean time-to-germinate (MTG) were studied after 30 days. The best FGP values were obtained in freshwater and low salinity conditions (1% and 1.5% NaCl). Moreover, similar MTG were observed at different salinities, but MTG was significantly high at lower temperature (i.e., 25 °C/15 °C). Finally, no differences between light conditions were observed. Our results suggest that salinity determines the germination and establishment of L. tobarrense, germinating successfully in freshwater and low salinity. In addition, a wide range of thermoperiod for its successful germination was found, although its interaction with the salinity was not significant. In consequence, L. tobarrense would germinate after the autumn rainfalls, when the salts are lixiviated in soil, and the medium temperature are favourable for the best seed germination conditions. Thus, specific environmental conditions would allow the own regeneration and adult niche of this endemism.

Navigating new realities: Explaining programmatic transitions of mainstream and niche parties

Electoral competition is determined by the issues that parties choose to compete on and the stances they adopt on these issues. However, little research has examined the trade-off between expanding a party’s programmatic stances to secondary issues while maintaining ideological continuity on primary issues. This article seeks to address this gap by examining programmatic transitions among mainstream and niche parties and in which contexts these transitions are more frequent. The study analyses 47 parties in 10 established democracies between 1986 and 2020 using multiple regression techniques. The results show that niche parties are more likely to focus on secondary issues, and when they make such transitions, they tend to be larger. The analysis also reveals that the length of niche competition influences mainstream parties’ programmatic transitions, while niche parties’ transitions are driven by their continuity in programmatic transitions and governmental experience.

Light Intensity: A Key Ecological Factor in Determining the Growth of Pseudolarix amabilis Seedlings

The notable absence of juvenile Pseudolarix amabilis trees in forest understories suggests their vulnerability to ecological niche competition, leading to limited survival prospects. This study examines the key factors limiting the growth of P. amabilis seedlings by investigating the effects of five ecological factors: light intensity, rainfall, groundwater level, soil type, and type of fertilization, on the growth of one-year-old P. amabilis seedlings. Our results demonstrate that increasing the light intensity promotes plant growth by augmenting the leaf count, leaf biomass, plant height, stem biomass, root biomass, and total biomass. Further analysis reveals that increased light intensity influences biomass allocation, reducing the specific leaf area and leaf–stem biomass ratio, and favoring root and stem growth over leaf investment. Rainfall, groundwater level, fertilization type, and rhizosphere soil type primarily influence root growth by impacting the soil’s physicochemical properties. Specifically, rising groundwater levels lower the soil temperature and increase the soil moisture, total potassium content, and soil pH, leading to reductions in root biomass, plant height, net height increment, leaf number, and total biomass. When groundwater levels reach 21 cm and 28 cm, submerging the surface soil layer, root biomass decreases by 1.6 g/plant (−51.6%) and 2.3 g/plant (−74.2%), respectively. Further analysis reveals a gradual decrease in the root–shoot ratio above the 14 cm groundwater level, while the specific leaf area and leaf–stem biomass ratio remains unaffected, indicating stronger belowground root stress compared to aboveground stem and leaf components. The results highlight light intensity as the key ecological factor determining the growth of P. amabilis seedlings. These findings underscore the importance of considering light intensity in the management of natural stands, the cultivation of artificial forests, and the nursery cultivation of endangered P. amabilis.

The Type VI secretion systems of the insect pathogen Photorhabdus luminescens are involved in interbacterial competition, motility and secondary metabolism

The Type VI Secretion System (T6SS) is used as weapon by a variety of Gram-negative bacteria in polymicrobial niche competition. Its characterization and study gained more interest in recent years. The system functions as a molecular nano-weapon: it is used in inter-kingdom competition by various bacteria to deliver toxic effectors in target cells. In this context, Photorhabdus luminescens subsp. luminescens strain DJC is a microorganism able to colonize different polymicrobial environments, like nematode guts, plant roots and larvae hemolymph. However, the mechanisms used by this microorganism to compete against other bacteria in the same environment have not been clearly described yet. We hypothesis that the T6SS of Photorhabdus luminescens subsp. luminescens strain DJC can play a role in same-niche environments. In this study we focused our attention on the characterization of the T6SS clusters in P. luminescens and its role in this bacteria lifestyle thought bioinformatic, proteomics analyses and inter-bacterial killing assays. Using bioinformatics analysis, we identified four T6SS gene clusters (T6SS-1, T6SS-2, T6SS-3 and T6SS-4) and multiple orphan T6SS related genes in the genome of P. luminescens. Furthermore, we highlighted 11 T6SS effector-immunity pairs, including three undescribed membrane disrupting effectors, each with putatively different antibacterial activities. By comparing the proteomes of P. luminescens wild type cells and the respective isogenic T6SS-deficient strains, we could point out a putative link between T6SS and other P. luminescens related defense mechanisms such as PVCs, T3SS and pyocins. Furthermore, T6SS-deficiency led to a change in phenotypic traits such as motility and secondary metabolism. Our findings shed light on the T6SS of P. luminescens DJC, suggesting a role of the system in the complex life cycle with a putative cross-link with various defense mechanisms and secondary metabolism. This study could help to gain more knowledge on bacterial T6SSs and better understand the P. luminescens ability to live in polymicrobial environments.

Niche partitioning and competition between different rabbit breeds using stable isotopes

Stable isotope analysis (SIA) is an evolving method for determining diet, understanding food web and resolving biogeochemical issues in the ecosystem. This study aims to trace out ecological niche preferences/partitioning and competition among the lagomorphs, including two different breeds of European rabbit (Oryctolagus cuniculus), New Zealand rabbit and American Dutch rabbit, using SIA. Thirty-two samples of tooth enamel were analysed, which were collected from different districts of Punjab, Pakistan, including Okara, Sahiwal and Kasur. Among these samples, 16 belonged to the New Zealand breed (08 male and 08 female rabbits) and 16 to the American Dutch breed (08 male and 08 female rabbits). Significant (P&lt;0.001) intergender differences in the isotope content of δ13C in the enamel for New Zealand and American Dutch rabbit were found. The European rabbits showed significant differences for both genders in the stable isotope of oxygen in the enamel (δ18O) values (P=0.05). Nitrogen stable isotope results showed no significant intergender differences between American Dutch and New Zealand rabbits (P=0.24). The stable isotope results for δ13C, δ15N, and δ18O indicate that the trophic niche partitioning of both breeds overlaps, which can potentially cause competition for resources, whereas the water intake may differ among different genders, which may reflect differential gender-related activities. The archaeological and fossilised data of lagomorphs is present, but there is no significant literature available for living lagomorphs (rabbits). In general, this study provides a basic and first dataset for δ13C, δ15N, and δ18O of living lagomorphs, which can serve as a comparative dataset for future studies.

Novel insights into safety and quality enhancement of low-salt fermented chilies: High-order positively interacting lactic acid bacteria co-fermentation regulates microflora structure, metabolomics, and volatilomics profiles

Microbial interactions, with their impact on community structure and function, emerge as a promising strategy for regulating low-salt fermented foods' safety and quality. Here, the mechanisms of microbial interaction on the safety and quality improvement of low-salt fermented chilies (LSFC) were untangled through high-throughput sequencing, gas chromatography-mass spectrometry, interaction networks, co-fermentation, and multivariate statistical analyses. Results showed that 4 spoilage microorganisms (Acinetobacter, Cronobacter, Enterobacter, and Klebsiella), 139.96 mg/kg of biogenic amines, and 13 off-flavor compounds affected the safety and quality of low-salt fermented chilies. Moreover, bacterial communities, mainly lactic acid bacteria (LAB) communities (relative abundance of 58.27–66.38%), were the primary contributors of volatile metabolites (diversity: R2 = 0.60; structure: R2 = 0.48; P < 0.001). Multiple interactions among LAB were quantified, including positive (11.7%), negative (55.0%), and neutral interactions (33.3%), in which positively interacting LAB community enhanced the robustness of in-situ community, resulting in the decrease of biogenic amines (decreased to 8.21 mg/kg) and the increase of the inhibition rate of Enterobacter hormaechei (inhibition rate of 80.31%). Additionally, co-fermentation experiments showed that the higher-order positively interacting LAB community (Leu. mesenteroides, Lac. plantarum, and Lac. brevis) corrected the microecological imbalance of the LSFC, increasing the content of linalool, 2,3-butanediol, and ethyl phenylacetate, and decreasing spoilage bacteria abundance and off-flavor compound types by 53.25% and 61.54%, respectively. Overall, the compatibility and niche competition between positively interacting communities and in-situ communities affect the microbial structure and function in LSFC. These findings provide new insights into enhancing low-salt fermented foods' biochemical safety and flavor quality.

Shigella sonnei utilises colicins during inter-bacterial competition.

The mammalian colon is one of the most densely populated habitats currently recognised, with 1011-1013 commensal bacteria per gram of colonic contents. Enteric pathogens must compete with the resident intestinal microbiota to cause infection. Among these enteric pathogens are Shigella species which cause approximately 125 million infections annually, of which over 90 % are caused by Shigella flexneri and Shigella sonnei. Shigella sonnei was previously reported to use a Type VI Secretion System (T6SS) to outcompete E. coli and S. flexneri in in vitro and in vivo experiments. S. sonnei strains have also been reported to harbour colicinogenic plasmids, which are an alternative anti-bacterial mechanism that could provide a competitive advantage against the intestinal microbiota. We sought to determine the contribution of both T6SS and colicins to the anti-bacterial killing activity of S. sonnei. We reveal that whilst the T6SS operon is present in S. sonnei, there is evidence of functional degradation of the system through SNPs, indels and IS within key components of the system. We created strains with synthetically inducible T6SS operons but were still unable to demonstrate anti-bacterial activity of the T6SS. We demonstrate that the anti-bacterial activity observed in our in vitro assays was due to colicin activity. We show that S. sonnei no longer displayed anti-bacterial activity against bacteria that were resistant to colicins, and removal of the colicin plasmid from S. sonnei abrogated anti-bacterial activity of S. sonnei. We propose that the anti-bacterial activity demonstrated by colicins may be sufficient for niche competition by S. sonnei within the gastrointestinal environment.

Inter-species interactions between two bacterial flower commensals and a floral pathogen reduce disease incidence and alter pathogen activity.

Fire blight, caused by Erwinia amylovora, is one of the most important plant diseases of pome fruits. Previous work largely suggested plant microbiota commensals suppressed disease by antagonizing pathogen growth. However, inter-species interactions of multiple flower commensals and their influence on pathogen activity and behavior have not been well studied. Here, we show that co-inoculating two bacterial strains that naturally colonize the apple flowers reduces disease incidence. We further demonstrate that the interactions between these two microbiota commensals and the floral pathogen led to the emergence of new gene expression patterns and a strong alteration of the external pH, factors that may modify the pathogen's behavior. Our findings emphasize the critical role of emergent properties mediated by inter-species interactions between plant microbiota and plant pathogens and their impact on plant health.

Does Packaging in Green Pay off? Role of Green Packaging on Firm Performance: Evidence from a Developing Economy

Purpose: Greening supply chains has become important more than ever among business firms carving out competitive niches. With the ever increasing complexity in business operations characterised by demand for higher value, supply chain firms are increasingly turning to green practices to not only achieve better results but also be socially responsible. While this is so, Euro monitor International report, 2020 discloses that globally, the manufacturing sector experienced 4.6% drop in market share by 2021, partly orchestrated by environmental upheavals due to business practices. The study sought to examine whether adopting green packaging pays off by establishing effect of green packaging on firm performance in a developing economy, Kenya.&#x0D; Methodology: The study achieved this through a mixed methods design on a population of 460 managers and 92 CEOs, interacted through a structured questionnaire and interview schedule. Standard linear regression in SPSS version 24 and thematic analysis were adopted. Results show that green packaging has significant positive effect on performance (R2=.394, β=.628, p&lt;.05), practically denoting that unit increase of packaging in green results to 0.628 units improvement in performance.&#x0D; Findings: The results provide sufficient evidence that indeed, packaging in green pays off. Further, the paper ground theoretical puts by Hart (1995) that green packaging is a pivotal resource.&#x0D; Unique contributor to theory, policy and practice: We provide interesting conclusions that green packaging pays off, advising managers and industry stakeholders to adopt policies of leveraging it. A research agenda is offered to further scholarly subsequent discussions.