An increase in antibiotic resistance and a corresponding decrease in antimicrobial drug discovery have resulted in researchers focussing on alternative therapies, including plant based medicines. The development of bacterial strains resistant to /3-lactam, including resistance to the second generation drugs methicillin, is particularly concerning and has rendered many common therapies ineffective or of substantially decreased efficacy. New antibiotic therapies are urgently needed. The antibacterial activity of selected southern African Combretum spp. leaf extracts towards /3-lactam resistant and sensitive bacterial strains was investigated by disc diffusion assays and quantified by broth microdilution Minimum inhibitory concentration (MIC) assays. Toxicity was evaluated by testing Artemia nauplii mortality and human dermal fibroblast (HDF) cytotoxicity assays. The gas chromatography coupled to Mass spectrometry (GC-MS) headspace analysis was used to identify volatile terpenoid components. The leaf extracts of all Combretum spp. displayed noteworthy growth inhibitory activity against all of the bacteria tested, including against Methicillin resistant Staphylococcus aureus MRSA, and the extended spectrum /3-lactamase (ESBL) strains of E. coli and K. pneumoniae. Combretum heroense leaf extract had particularly good (MICs = 170-680 mu g/mL) antibacterial activity against all bacterial strains. Notably, this extract was a better inhibitor of MRSA than of the /3-lactam sensitive strain of S. aureus. The Combretum vendae extract was also a good inhibitor of the MRSA and ESBL strains. Noteworthy antibacterial activity (MICs 120-890 mu g/mL) was also noted for Combretum collinum and Combretum molle extracts against all bacteria, and for the Combretum bracteosum and Combretum erythrophyllum extracts against the MRSA and ESBL strains (500-1625 mu g/mL). All extracts were non-toxic in the Artemia nauplii lethality assay (ALA) and HDF assays and the calculated therapeutic indexes (TIs) indicated their safety for use as antibiotic chemotherapies. The GC-MS headspace analysis identified and highlighted several noteworthy monoterpenoids which had antibacterial properties. In particular, cineole, terpineol, camphor, borneol and limonene were present in relative abundance in all Combretum spp. extracts. Further phytochemical and mechanistic studies of these extracts are warranted. (c) 2023 The Author(s). Published by Elsevier B.V. on behalf of SAAB. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

The escalating global crisis of bacterial resistance to antibiotics poses a threat to public health. Urgent measures are required to identify novel antibacterial treatments. Multidrug-resistant bacterial strains limit the effective therapeutic options available, raising concerns about a post-antibiotic era and a reduced ability to treat infections that were previously not classified as serious. Simultaneously, the threat of emerging infectious diseases, including zoonotic pathogens, underscores the need to develop effective antibiotics against these pathogens. Innovative approaches to antibiotic development, such as novel chemical scaffolds, combination therapies, antimicrobial peptides, and phage therapy, show promise but require the discovery of new antibacterial compounds. Desert and rainforest ecosystems, despite being disparate in climate and biodiversity, offer unique prospects for developing antibacterial compounds. Deserts, which are characterized by extreme aridity and temperature fluctuations, harbor plants and micro-organisms with specialized antibacterial defences honed through evolution. Conversely, rainforests, with their biodiversity and high humidity, are promising for the development of potential antibacterial compounds. To date, much natural product research aimed at discovery of new antibiotic compounds has focussed on rainforest plants due to the biodiversity of these ecosystems, and because plants develop chemical defences against microbes that are prevalent in those environments. In comparison, the search for new antimicrobial compounds from desert plants has been overshadowed, despite some noteworthy antibacterial activities in arid environment plants. This commentary discusses the comparative potential of desert and rainforest ecosystems as reservoirs of novel antibacterial agents and emphasises the importance of screening plants in both environments.

Introduction:Eucalyptus baileyana (Bailey's stringy bark) and Eucalyptus major (Queensland grey gum) have been previously used as antimicrobials against a variety of ailments.This study evaluated the effectiveness of E. baileyana and E. major as inhibitory agents against Shewanella putrefaciens, a bacterium widely associated with fish spoilage.Methodology: E. baileyana and E. major extracts were prepared using the leaves of each plant with methanol or water as the extraction solvent.Growth inhibition and minimal inhibitory concentrations were determined against S. putrefaciens through disc diffusion assays.MIC values were subsequently quantified to evaluate the extracts efficacies as antibacterial agents.Finally, the toxicity of each extract was determined using the Artemia franciscana nauplii bioassay.Results: E. baileyana aqueous and methanolic leaf extracts inhibited the growth of S. putrefaciens in the disc diffusion assay, with MIC values of 1411 and 1221 μg/mL respectively.Similarly, E. major leaf extracts also showed growth inhibition of S. putrefaciens, with MIC values of 1686 μg/mL for the aqueous extract, and 1160 μg/mL for the methanolic extract.However, toxicity studies of the extracts revealed that all extracts were toxic and likely unsuitable for human consumption (LC 50 values 455-1146 μg/mL) as determined by the Artemia franciscana bioassay.Conclusion: While the E. baileyana and E. major leaf extracts were effective in preventing microbial growth, given their relatively high levels of toxicity, they would not be suitable for use as a preservative in the prevention of fish spoilage.However, the antibacterial capacity of the extracts indicates that the extracts may show promise as a surface disinfectant, and this should be investigated further.

Halomonas sp. strain KAO is an aerobic, Mn(II)-oxidizing, halophilic bacterium. The draft genome of the isolate contains 47 contigs encompassing 3.7 Mb and a G+C content of 64.22%. This sequence will provide essential information for future studies of Mn(II) oxidation, particularly under halophilic conditions.

Halomonas sp. strain ML-15 is an aerobic, haloalkaliphilic bacterium capable of degrading polycyclic aromatic hydrocarbons (PAHs). The draft genome sequence of the isolate contains 19 contigs encompassing 4.8 Mb and a G+C content of 65.38%. This sequence will provide essential information for future studies of PAH degradation, particularly under haloalkaliphilic conditions.

Pharmacognosy Communications, Vol 10, Issue 2, Apr-Jun, 2020 95 ABSTRACT Introduction: Acronychia acidula F. Muell. (lemon aspen, pigeon berry) has been previously recognized for its antimicrobial properties against a broad panel of pathogenic bacteria. This study assessed the effectiveness of A. acidula as an inhibitory agent against bacteria associated with malodour formation. Methodology: A. acidula fruit extracts were prepared using methanol or water as the extraction solvent. Growth inhibition and minimal inhibitory concentrations were determined against C. jeikeium, P. acnes and B. linens through disc diffusion assays. MIC values were quantified to evaluate their efficacies as antimicrobials. Toxicity of each extract was determined using the Artemia franciscana nauplii bioassay. Results: A. acidula aqueous fruit extracts inhibited the growth of B. linens (MIC = 1258 μg/mL), C. jeikeium (MIC = 1630 μg/mL) and P. acnes (MIC = 1455 μg/mL) in the disc diffusion assay. Similarly, the methanolic fruit extracts inhibited the growth of B. linens (MIC = 2608 μg/mL) and C. jeikeium (MIC = 3044 μg/mL), although no growth inhibition of P. acnes was observed. Both aqueous and methanolic A. acidula extracts were nontoxic towards Artemia nauplii (LC50 values of 1872 μg/mL and 1500 μg/mL). Conclusion: A. acidula fruit extracts were non-toxic and also displayed moderate growth inhibitory bioactivity against B. linens, C. jeikeium and P. acnes, highlighting their potential as additives to deodorants.

Introduction: Yersinia enterocolitica is a major source of food poisoning via the consumption of contaminated meat products, causing acute gastroenteric yersiniosis. Tasmannia lanceolata has been widely documented for its antiseptic properties, repressing the growth of an extensive range of bacteria. Despite this, Tasmannia lanceolata has yet to be been tested for its inhibitory capacity against Y. enterocolitica. Methods: T. lanceolata leaf and berry extracts were prepared by maceration and growth inhibitory activity against a clinical strain of Y. enterocolitica was examined by disc diffusion assays. The MIC values of the extracts were determined to quantify and compare their relative efficacies. Toxicity was determined using an Artemia franciscana nauplii bioassay. Results: T. lanceolata leaf and berry extracts displayed potent growth inhibitory activity in the disc diffusion assay against Y. enterocolitica. The ethyl acetate and chloroform leaf extracts (MICs of 30 and 53 μg/mL respectively) and the hexane berry extract (MIC = 34 μg/mL) were particularly potent growth inhibitors. The methanol and water extracts of both the berry and leaf, as well as the leaf ethyl acetate extract, also had strong growth inhibitory activity against Y. enterocolitica, albeit with a higher MIC values (250-300μg/mL). All other extracts had lower efficacy, although their MIC values also indicated good inhibitory activity (with the exception of the chloroform berry extract). When assessed for toxicity, all T. lanceolata extracts were non-toxic (LC50 values >1000 μg/mL) in the Artemia franciscana bioassay. Conclusion: The non-toxicity of the T. lanceolata berry and leaf extracts, combined with the potent inhibitory bioactivity observed against Y. enterocolitica, demonstrates their potential as therapeutic agents in the prevention and treatment of yersiniosis.

Introduction: Bacillus anthracis is bacterial cause of the highly fatal, zoonotic disease anthrax. Tasmanian pepper (Tasmannia lanceolata) has been previously documented for its antiseptic properties against other pathogenic bacteria. This study sought to investigate the effectiveness of T. lanceolata as an inhibitory agent against B. anthracis. Methods: Tasmannia lanceolata berry and leaf extracts were prepared with either water or methanol as the extraction solvent. Growth inhibition was assessed against B. anthracis strain PMO through disc diffusion as assaying. The relative MIC values of each extract was quantified to evaluate efficacy as a sterilant. The degree of toxicity of each extract was achieved using the widely used Artemia franciscana nauplii bioassay. Results: T. lanceolata leaf extracts inhibited the growth of B. anthracis in the disc diffusion assay, with MIC values of 2333 and 1873 μg/mL respectively. In contrast, the T. lanceolata berry extracts were completely devoid of growth inhibitory activity. All T. lanceolata extracts (both berry and leaf) were non-toxic (LC50 values substantially >1000 μg/mL) as determined via the Artemia franciscana bioassay. Conclusion: T. lanceolata berry and leaf extracts are not only non-toxicity, but also had moderate growth inhibitory bioactivity against B. anthracis, highlighting their potential in the treatment of anthrax.

Objective Recently, our group reported that extracts prepared from the Australian native plant Terminalia ferdinandiana Exell. are potent inhibitors of the growth malodorous bacteria with similar efficacy to triclosan and through these results, we highlighted a potential biological alternative to the current chemical additives. Other members of the genus Terminalia are also well documented for their antibacterial potential and tannin contents and thus were investigated as potential deodorant additives. Methods Solvent extractions prepared from of selected Indian, Australian and South African Terminalia spp. were screened by disc diffusion and liquid dilution assays against C. jeikeium, S. epidermidis, P. acnes and B. linens. The antibacterial activity was quantified by liquid dilution MIC assays. The extracts were screened for toxicity using Atremia franciscana nauplii and HDF cell viability bioassays. High-resolution time-of-flight (TOF) LC-MS and GC-MS headspace fingerprint analysis was used to detect tannin, flavonoid and terpenoid components in the extracts. Results Bacterial growth inhibition was observed in all Terminalia extracts with the methanolic T. chebula, T. carpenteriae and T. sericea extracts the most promising bacterial growth inhibitors, yielding MIC values as low as 200 mu g mL(-1). Toxicity analyses of the extracts were favourable, and we determined that the methanolic T. chebula, T. carpenteriae and T. sericea extracts were all non-toxic. Using previously detected T. ferdinandiana antimicrobials as benchmarks, LC-MS and GC-MS fingerprint analyses revealed similar compounds in the methanolic T. chebula, T. carpenteriae and T. sericea extracts. Conclusion Through these results, we propose that Terminalia spp. extracts may be useful deodorant additives to inhibit the growth of axillary and plantar malodorous bacteria, offering a biological alternative to their chemically synthesized counterparts.

Introduction: An aerobic, Mn(III)-oxidizing, Gram-negative, motile bacterium (strain GSL-010T) was isolated from deep waters of the St Lawrence Estuary (Canada) and subjected to a polyphasic taxonomic study. Results: Cells were mostly curved, motile rods (1.75 – 2.2 x 0.5 – 0.7 μm) with growth observed at 10 – 37 oC (optimum at 30 oC), pH 5 – 10 (optimum at 7.0 – 7.5) and with 0 – 3% (w/v) NaCl (optimum at 0.5%). Phylogenetic analysis based on 16S rRNA gene sequencing revealed strain GSL-010T as a member of the genus Pseudomonas, most closely related to the type strains of Pseudomonas plecoglossicida (98.9%) and Pseudomonas japonica (98.6%). The major cellular fatty acids of strain GSL-010T are a combination of C16:1 ω7c and/or iso-C15:1 2-OH, C16:0 and C18:1 ω7c. The G+C mol content of the chromosomal DNA is 59.7%. The DNA–DNA hybridization values between strain GSL-010T and P. plecoglossicida (32.0%) and P. japonica (34.4%) confirm the assignment of the bacterium to a new species. Conclusion: On the basis of phylogenetic analysis, DNA–DNA hybridization and physiological and biochemical characterization, strain GSL-010T is clearly a unique bacterium and since it was isolated from the waters of the St. Lawrence estuary, the name Pseudomonas laurentiana sp. nov. is proposed. The type strain is GSL-010T (=JCM 32154T =NBRC 113027T =KCTC 62392T).

Shewanella spp. are major causes of fish spoilage. Terminalia ferdinandiana (Kakadu plum) extracts were investigated for their ability to inhibit Shewanella spp. growth. Leaf and fruit extracts displayed potent growth inhibitory properties against all Shewanella spp. The methanolic leaf extract was a particularly potent inhibitor of S. putrefaciens (DD MIC 93; LD MIC 73 μg/mL), S. baltica (DD MIC 104 μg/mL; LD MIC 85 μg/mL), S. frigidimarina (DD MIC 466 μg/mL; LD MIC 391 μg/mL) and S. loihica (DD MIC 95 μg/mL; LD MIC 55 μg/mL) growth. The aqueous and ethyl acetate leaf extracts were also potent growth inhibitors, with MIC values generally substantially <1000 μg/mL. Treatment of Acanthopagrus butcheri Munro fillets with methanolic Kakadu plum extracts significantly inhibited bacterial growth for 15 days at 4 °C. All Kakadu plum extracts were nontoxic in the Artemia franciscana bioassay. LC-MS analysis identified several compounds which may contribute to the inhibition of Shewanella spp. growth.

The observation of significant concentrations of soluble Mn(III) complexes in oxic, suboxic and some anoxic waters has triggered a re-evaluation of the previous Mn paradigm; which focused on the cycling between soluble Mn(II) and insoluble Mn(III,IV) species as operationally defined by filtration. Though Mn(II) oxidation in aquatic environments is primarily bacterially-mediated, little is known about the effect of Mn(III)-binding ligands on Mn(II) oxidation nor on the formation and removal of Mn(III). Pseudomonas putida GB-1 is one of the most extensively investigated of all Mn(II) oxidizing bacteria, encoding genes for three Mn oxidases (McoA, MnxG and MopA). P. putida GB-1 and associated Mn oxidase mutants were tested alongside environmental isolates Pseudomonas hunanensis GSL-007 and Pseudomonas sp. GSL-010 for their ability to both directly oxidize weakly and strongly bound Mn(III), and to form these complexes through the oxidation of Mn(II). Using Mn(III)-citrate (weak complex) and Mn(III)-DFOB (strong complex), it was observed that P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 and mutants expressing only MnxG and McoA were able to directly oxidize both species at varying levels; however, no oxidation was detected in cultures of a P. putida mutant expressing only MopA. During cultivation in the presence of Mn(II) and citrate or DFOB, P. putida GB-1, P. hunanensis GSL-007 and Pseudomonas sp. GSL-010 formed Mn(III) complexes transiently as an intermediate before forming Mn(III/IV) oxides with the overall rates and extents of Mn(III,IV) oxide formation being greater for Mn(III)-citrate than for Mn(III)-DFOB. These data highlight the role of bacteria in the oxidative portion of the Mn cycle and suggest that the oxidation of strong Mn(III) complexes can occur through enzymatic mechanisms involving multicopper oxidases. The results support the observations from field studies and further emphasize the complexity of the geochemical cycling of manganese.

Background: Extracts produced from S. australe and S. luehmannii fruit and leaves are potent growth inhibitors of many bacterial pathogens. They may also inhibit the growth of malodour producing bacteria and thus be useful deodorant components, although this is yet to be tested. Methods: S. australe and S. luehmannii fruit and leaf solvent extracts were investigated by disc diffusion assays against significant bacterial contributors to axillary and plantar malodour formation. Toxicity was determined using the Artemia franciscana nauplii bioassay. Results: S. australe and S. luehmannii solvent extracts were good inhibitors of B. linens and C. jeikeium growth, with zones of inhibition up to 10 mm measured. S. australe extracts were generally better inhibitors of both bacterial species compared with the S. luehmannii extracts. Ethyl acetate extracts were particularly potent, with MIC values of 300 and 857 µg/mL for the S. australe fruit and leaf extracts respectively against B. linens , and 1000 and 311 µg/mL against C. jeikeium . The S. luehmannii fruit ethyl acetate extracts were similarly potent growth inhibitors, with MIC values of 571 and 203 µg/mL against B. linens and C. jeikeium respectively. S. australe aqueous and methanolic leaf extracts were also potent inhibitors of C. jeikeium (MIC’s of 285 and 306 µg/mL respectively). All other extracts had moderate or low inhibitory activity. All of the most potent ethyl acetate extracts were nontoxic in the Artemia franciscana bioassay. In contrast, the methanolic and aqueous S. australe leaf extracts, as well as the aqueous and methanolic S. luehmannii fruit extracts displayed apparent toxicity. However, these results may be fallacious and instead result from the high antioxidant content of these extracts. Conclusion: The potent growth inhibition of axillary and plantar malodour producing bacteria by the Syzygium spp. extracts indicate their potential as deodorant components.

Introduction: Clostridium perfringens is the etiological agent of clostridial myonecrosis and enteritis necroticans. Infections result in exotoxin production, tissue necrosis and unless promptly treated, often result in death. Methods: Tasmannia lanceolata extracts were investigated for C. perfringens growth inhibitory activity by disc diffusion analysis and MIC determination. Toxicity was evaluated by Artemia nauplii bioassay and the most potent extracts were phytochemically evaluated by GC-MS headspace analysis. Results: All T. lanceolata berry and leaf extracts displayed potent C. perfringens growth inhibition. The berry extracts were more potent growth inhibitors than the corresponding leaf extracts, although the leaf extracts were also potent growth inhibitors. The berry aqueous, methanolic and ethyl acetate extracts were particularly potent growth inhibitors, with MIC values of 654, 65 and 329 μg/mL respectively. T. lanceolata leaf also displayed good efficacy, with an MIC of 839, 1255 and 625 μg/mL for the aqueous, methanolic and ethyl acetate extracts respectively. All extracts were nontoxic in the Artemia franciscana bioassay, with LC50 values substantially > 1000 μg/mL. Non-biased GC-MS analysis of the aqueous, methanolic and ethyl acetate berry extracts revealed the presence of high relative levels of a diversity of terpenoids. Conclusions: The lack of toxicity of the T. lanceolata extracts and their potent growth inhibitory bioactivity against C. perfringens indicates their potential as medicinal agents in the treatment and prevention of clostridial myonecrosis and enteritis necroticans. GC-MS metabolomic profiling studies indicate that these extracts contained a diversity of terpenoids, with monoterpenoids being particularly abundant.

Marmur (4) developed one of the first detailed comprehensive methods for purifying bacterial DNA. This procedure is now outdated, and can be difficult to follow for those with limited experience in molecular biology. Here, we provide a modernized, simplified protocol for extracting bacterial DNA and discuss how this can be incorporated into microbiology laboratory courses for biology majors.

OBJECTIVE: Terminalia ferdinandiana extracts are potent growth inhibitors of many bacterial pathogens. They may also inhibit the growth of malodour-producing bacteria and thus be useful deodorant components, although this is yet to be tested.METHODS: Terminalia ferdinandiana fruit and leaf solvent extracts were investigated by disc diffusion and liquid dilution MIC assays against the most significant bacterial contributors to axillary and plantar malodour formation. Toxicity was determined using the Artemia franciscana nauplii bioassay. Non-targeted HPLC separation of the methanolic leaf extract coupled to high-resolution time-offlight (TOF) mass spectroscopy was used for the identification and characterization of individual components in the extract.RESULTS: The T. ferdinandiana leaf extracts were the most potent bacterial growth inhibitors. The leaf methanolic extract was particularly potent, with low MIC values against C. jeikeium (233 mu g mL(-1)), S. epidermidis (220 mu g mL(-1)), P. acnes (625 mu g mL(-1)) and B. linens (523 mu g mL(-1)). The aqueous and ethyl acetate leaf extracts were also potent growth inhibitors of C. jeikeium and S. epidermidis (MICs < 1000 mu g mL(-1)). In comparison, the fruit extracts were substantially less potent antibacterial agents, although still with MIC values indicative of moderate growth inhibitory activity. All T. ferdinandiana leaf extracts were non-toxic in the Artemia franciscana bioassay. Non-biased phytochemical analysis of the methanolic leaf extract revealed the presence of high levels of and high diversity of tannins and high levels of the flavone luteolin.CONCLUSION: The low toxicity of the T. ferdinandiana leaf extracts and their potent growth inhibition of axillary and plantar malodour-producing bacteria indicate their potential as deodorant components.

Syzygium australe and Syzygium luehmannii fruit and leaf were investigated for their ability to inhibit Shewanella spp. growth. Extracts of both Syzygium spp. displayed potent growth inhibitory properties against all Shewanella spp. tested in disc diffusion and liquid diffusion assays. In general, S. australe extracts were more potent inhibitors of Shewanella spp. growth, and the fruit extracts were generally better than the corresponding leaf extracts. The methanolic S. australe fruit extract was a particularly potent inhibitor of all Shewanella spp. growth, with MIC values as low as 87 µg/mL. The aqueous and ethyl acetate S. australe fruit extracts were similarly potent inhibitors of Shewanella spp. growth, albeit with slightly higher MIC values. Several other Syzygium spp. extracts also were potent bacterial growth inhibitors, albeit with MIC values generally >1000 µg/mL. The most potent S. australe fruit extracts were nontoxic in the Artemia franciscana bioassay, with LC50 values substantially >1000 µg/mL. The potent bacterial growth inhibitory activity and lack of toxicity of the S. australe fruit extracts indicate their potential as natural fish and seafood preservatives.

Introduction: Yersinia enterocolitica is a major cause of food poisoning through contaminated meat products, causing the acute gastrointestinal disease yersiniosis.Many Terminalia spp.have documented therapeutic properties as general antiseptics, inhibiting the growth of a wide variety of bacterial species.Despite this, Indian Terminalia spp.extracts have not been tested for the ability to inhibit the growth of Y. enterocolitica.Methods: T. arjuna, T. catappa and T. chebula extracts were extracted by maceration and the extracts were investigated by disc diffusion assay for growth inhibitory activity against a clinical strain of Y. enterocolitica.The MIC values of the extracts were determined to quantify and compare their efficacies.Toxicity was determined using the Artemia franciscana nauplii bioassay.Results: T. chebula fruit extracts displayed potent growth inhibitory activity in the disc diffusion assay against Y. enterocolitica.The methanolic and ethyl acetate T. chebula fruit extracts were particularly potent growth inhibitors, with MIC values of 85 and 64 µg/mL respectively.The aqueous fruit extract also displayed good growth inhibitory activity against Y. enterocolitica, albeit with a higher MIC value (653 µg/mL).The T. arjuna branch extract was moderately active (3000 µg/mL).All other extracts were either low efficacy, or completely devoid of growth inhibitory activity.All Indian Terminalia spp.extracts were nontoxic (LC 50 values <1000 µg/mL) in the Artemia franciscana bioassay.Conclusions: The lack of toxicity and the potent growth inhibitory bioactivity of the T. chebula extracts against Y. enterocolitica indicates their potential as medicinal agents in the treatment and prevention of yersiniosis.

Introduction:Anthrax is a severe acute disease caused by Bacillus anthracis infections.If untreated, it often results in mortality.Many Terminalia spp.have documented therapeutic properties as general antiseptics, inhibiting the growth of a wide variety of bacterial species.This study examines the ability of selected Australian Terminalia spp.extracts to inhibit B. anthracis growth.Methods:Solvent extracts were prepared from Terminalia carpen tariae and Terminalia grandiflora plant material and investigated by disc diffusion assay for the ability to inhibit the growth of an environmental strain of B. anthracis.Their MIC values were determined to quantify and compare their efficacies.Toxicity was determined using the Artemia franci scana nauplii bioassay.The most potent extracts were analysed by GC-MS headspace analysis.Results: T. carpentariae and T. grandiflora leaf, fruit and nut solvent extractions displayed good growth inhibitory activity against B. anthracis.Methanolic T. carpentariae leaf and T. grandiflora nut extracts were particularly potent growth inhibitors, with MIC values of 74 and 155 µg/mL respectively.The T. carpentariae leaf ethyl acetate extract was also a good inhibitor of B. anthracis growth (MIC 340 µg/mL).All other extracts were substantially less potent growth inhibitors.Interestingly, the T. carpentariae leaf extracts with growth inhibitory activity were nontoxic in the Artemia fransiscana bioassay, with LC 50 values >1000 µg/mL.In contrast, the LC 50 value 740 µg/mL reported for the methanolic T. grandiflora nut extract indicates low-moderate toxicity.Non-biased GC-MS phytochemical analysis of the most active extracts (methanolic T. carpentariae leaf and T. grandiflora nut) putatively identified and highlighted several compounds that may contribute to the ability of these extracts to inhibit the growth of B. anthracis.Conclusion: The growth inhibitory activity of the metha nolic T. carpentariae leaf and T. grandiflora nutextracts against B. anthracis indicates their potential for the treatment and prevention of anthrax.Furthermore, the lack toxicity of the T. carpentariae leaf and the low-moderate toxicity of the T. grandiflora nut extract, indicates that their use may extend to all forms of the disease (cutaneous, inhalation or gastrointestinal).