Table 2.

Research on the in vitro antimicrobial activity of Arthrospira platensis.

Extract or Sample	Test Microorganism	Antibacterial Activity: MIC, MBC, IZ, etc.	Test Methods	Reference
Ethanol (EtOH):water (70:30) extract	E. coli, S. aureus, Bacillus cereus, Listeria monocytogenes Salmonella spp. (isolates from pigs), Salmonella enterica (incl. serotype Rissen)	Most effective after 24 h treatment IZs from 9 to 15 mm (most active against B. cereus, L. monocytogenes, S. aureus) Bacteriostatic activity at 0.45% (v/w) Bactericidal effect at 0.9% (v/w)	AWDM, In situ MCT (L. monocytegenes contamination of salmon tartare)	[88]
EtOH extract 300 mg/mL	Clinical isolates of Enterococcus fae-calis, E. coli, Proteus mirabilis, P. aeruginosa, S. aureus, Staphylococcus lentus, Staphylococcus xylosus, Streptococcus agalactiae, S. pyogenes	IZ = 21.6 mm (S. agalactiae), highest activity IZ = 8.5 mm (P. aeruginosa), lowest activity	AWDM	[148]
Sodium acetate buffer extract (SA) Aqueous extract Chloroform (CHCl3)–MeOH extract	Staphylococcus sp. isolates (19 strains) causing goat mastitis and Staphylococcus sp. isolates (16 strains) causing bovine mastitis	MIC50 = 12 μg/mL (bovine mastitis strains) MIC = 100 μg/mL (aqueous extract) MIC50 = 3, 6–50 μg/mL (goat mastitis strains) MIC = 25 μg/mL SA and aqueous extracts) MIC > 100 μg/mL (CHCl3–MeOH extract)	BMD	[151]
Suspension	S. aureus E. coli Candida albicans	MIC/MBC = 500/500 ppm MIC/MBC = 125/250 ppm MIC/MBC = 62.5/125 ppm IZs = 1.4 mm at 500 ppm 1.6 mm at 1000 ppm), 8.55 mm at 500 ppm and 15.6 mm at 250 ppm	BMD Disc diffusion method (DDM) Agar plate assay	[79]
The dominant hydrolyzed spirulina protein (HSP) Peptide fractions (PF)	E. coli S. aureus	MIC = 625 μg/mL (both HSP and PF) HSP stimulated the bacterial growth PF < 3 kDa inhibited E. coli and S. aureus growth to 15.2 and 19.6% after 16 h	BMD	[149]
Aqueous extract	S. aureus, P. aeruginosa, E. coli, Stenotrophomonas maltophiliastrains	No antibacterial activity	DDM	[145]
MeOH, EtOH, EtOAc, CHCl3 extracts	Multidrug-resistant S. aureus, E. coli, P. aeruginosa, Salmonella sp. and Shigella sp.	Bacterial growth inhibition of 67–98% Most effective extract: MeOH	Kirby-Bauer single-disk diffusion agar method	[150]
Ether, hexano–EtOH, DCM, acetone and MeOH extracts	S. aureus, B. cereus, B.subtilis, E. coli, Klebsiella sp, P. aeruginosa, S. typhimurium (ATCC strains) Fungi—C. albicans and Aspergillus brosiliensis	IZs = 0–43 mm MIC (MeOH extract) = 128 μg/mL against B. subtilis was Moderate effect on C. albicans Reistance towards A. brosiliensis	AWDM DDM	[152]
MeOH extract (100 ng/mL)	V. parahaemolyticus, V. alginolyticus, other Vibrio sp. Chromobacterium violaceum, S. aureus, P. aeruginosa, E. coli, S. marsecens, A. hydrophila	Biofilm inhibition: ~90% (V. parahaemolyticus), 89% (C. violaceum), 88% (V. alginolyticus), 74% (A. hydrophila), 69–72% (P. aeruginosa), 62% (E. coli), 61–84% (S. aureus), 49% (S. marsecens) Extracellular polymeric substance inhibition: 80% (A. hydrophila), 62% (E. coli), 52–66% (S. aureus), less than 30% for the other strains CSH reduction: A. hydrophila, E. coli and S. aureus	Biofilm inhibition assay—spectrophotometric quantification AWDM BATH assay for CSH determination	[7]
MeOH, acetone, CHCl3, hexane extracts	E. coli, S. typhi, P. mirabilis, V. vulnificus and Cellulomonas cellulan	100 μg MeOH/CHCl3 extracts: IZ = 26/27 mm (E. coli), IZ = 21 mm (S. typhi), IZ = 24 mm (P. mirabilis)	AWDM DDM	[146]
EtOH and CHCl3 extracts	Salmonella enterica serovar typhi and paratyphi	40 mg/mL EtOH extract IZ = 10–14 mm (S. paratyphi), 10–16 mm for (S. typhi) CHCl3 extract—no inhibitory effect	DDM	[153]
Aqueous, hexane, CHCl3, EtOAc and 70% EtOH extracts	E. coli, A. hydrophila, S. enterica, Klebsiella pneumonie, V. cholera Salmonella Paratyphi, S. aureus and L. monocytogenes Fungi—Aspergillus terreus, Tirchoderma viride, Candida tropicalis and S. cerevisiae	Aqueous extract: no activity Hexane extract IZ = 11 mm (A. terreus) CHCl3 extract IZ = 21.5 mm (E. coli) EtOAc extract: small IZs on S. paratyphi and S. cerevisiae EtOH extract: moderate activity	DDM	[154]
MeOH extracts, pellet and aqueous extracellular supernatant from A. platensis	B. subtilis, E. coli, P. fluorescens Fungi—C. albicans and S. cerevisiae	MeOH extracts: IZ = 10 mm (E. coli), 1.3 mm (B. subtilis), IZ >10 mm (S. cerevisiae)	AWDM	[155]
Diethyl ether, EtOAc, petroleum ether, n-hexane, CHCl3, acetone, MeOH and EtOH extracts Unknown purified antimicrobial compound (PAC)	E. coli, P. aeruginosa, B. subtilis, B. thuringiensis, Fungi—S. cerevisiae, Aspergillus flavus and A. niger, C. albicans	E. coli, P. aeruginosa, B. Subtilis, A. niger were most sensitive Diethyl ether, EtOAc, EtOH extracts inhibited Gram (+) and Gram (-) bacteria; petroleum ether extract inhibited Gram (-); n-hexane extract—no activity MICs (PAC) = 30, 60, 65, 80, 85 µg/mL (C. albicans, B. subtilis, S. aureus, E. coli and P. aeruginosa) MICs (PAC) > 120 µg/mL (A. flavus, A. niger)	BMD	[144]
Aqueous and EtOH extract	S. marcescens, E. coli, B. cereus, M. luteus, S. aureus, K. pneumoniae and P. aeruginosa, A. flavus	EtOH extract: most active on E. coli and S. aureus B. cereus and K. pneumonie: most resistant Nitrogen-supplemented medium potentiated the extract’s activity	Agar plate diffusion test	[156]
70% EtOH, 70% MeOH, 70% EtOAc and 70% CHCl3 extracts	S. aureus isolates	EtOH > MeOH > CHCl3 > EtOAc	Microtiter plates reader assay BMD	[157]
Phycocyanin	S. aureus, S. pyogenes, B. cereus, E. coli, P. aeruginosa, S. typhimurium and C. albicans	MIC = 2.1 mg/mL for C. albicans and S. typhimurium	AWDM BMD	[65]
Dichloromethane (DCM)/MeOH extract, acetone soluble (ASF) and insoluble fraction (AIF) from it, aqueous extract, water insoluble fraction, phycocyanin and culture filtrate	Seven bacterial fish pathogens—A. hydrophila, B. subtilis, B. cereus, Edwardsiella tarda, M. luteus, V. parahemolyticus and V. alginolyticus	MICs of ASF = 1.9–15 µg/mL, MBCs (7.8–250 µg/mL) and highest IZs = 31–41 mm. E. tarda was the most susceptible pathogen to ASF AIF—moderate effect Phycocyanin IZ on A. hydrophila = 16 mm AFM of A. hydrophila showed cell wall decay	AWDM BMD Atomic force microscopy (AFM)	[139]
Live cells in a co-culture	Six Vibrio bacterial strains—V. parahaemolyticus, V. anguillarum, V. splendidus, V. scophthalmi, V. alginolyticus and V. lentus	Strong inhibition of bacterial growth ca. 1000 times after 96–120 h co-culturing V. alginolyticus and V. anguillarum: most resistant slower decrease in bacterial count	Co-culturing of microalgae or cyanobacteria with bacteria—OD measurement	[85]
Intracellular (food-grade solvent) and extracellular EtOH/water (1:1, v:v) extracts	S. aureus, Salmonella sp., E. coli and P. aeruginosa	Slight inhibition of all bacterial species	Mixtures of pathogens and cyanobacteria	[142]
MeOH and acetone extracts (concentration 250–7000 ppm)	S. aureus and S. typhimurium	IZ (acetone extract at 5000 ppm) = 21.5 mm (S. aureus) IZ (MeOH extract) = 17.5 mm (S. typhimurium)	AWDM DDM	[143]
EtOH extract	S. aureus, E. coli, P. aeruginosa, Klebsiella sp., Proteus sp., Embedobacter sp.—clinical isolates	IZs = 6–11 mm (11 mm against E. coli)	AWDM	[147]
Hexane, EtOAc, EtOH, butanol, acetone, MeOH and CHCl3 extracts	S. aureus, E. feacalis, S. epidermidis, Aeromonas liquefaciens, Campylobacter coli, Vibrio cholerae, Candida glabrata	IZs butanol extract = 19 mm (S. epidermidis), 18 mm (S. aureus, A. liquefaciens), 13 mm (C. glabrata), 12 mm (E. feacalis), 11 mm (C. coli and V. cholera) and 5 mm (S. typhi)	AWDM	[158]
Purified phycocyanin	S. aureus, Enterococcus durans, E. coli, K. pneumoniae, P. aeruginosa and Acinetobacter baumanii	IZ = 13.3 mm (E. coli), 16 mm (K. pneumoniae), 18 mm (P. aeruginosa), and 9.3 mm (S. aureus). MICs = 50–125 µg/mL No activity on A. baumanii and E. durans	BMD	[159]
EtOH, MeOH and aqueous extracts	Fish and shellfish pathogens—P. putida, P. aeruginosa, P. fluorescens, A. hydrophila, V. alginolyticus, V. anguillarum, V. fluvialis, V. parahaemolyticus, V. harveyi, V. fisheri, E. tarda and animal isolates of E. coli	EtOH extract: 16 mm IZ and MICs from 100 to 150 µg/mL for A. hydrophila EtOH extract: 12 to 15 mm IZs for Vibrio, E. coli and E. tarda	DDM MIC determined by the tube dilution method	[160]
Aqueous, MeOH, EtOH, acetone, petroleum ether and hexane extracts from the EPS or exopolysaccharides	S. aureus, Staphylococcus epidermidis M. luteus, E. coli, S. typhimurium and P. aeruginosa	MeOH extract: IZs = 7.5, 11 and 19.5 mm against M. luteus, S. typhimurium and P. aeruginosa, MIC = 1–10 mg/mL, MBC = 10 mg/mL Aqueous extract: IZs = 14 and 7 mm against S. epidermidis and S. typhimurium, MIC = 5 mg/mL and MBC = 12 mg/mL Neither extract was active against E. coli and S. aureus	DDM BMD	[161]
Phenolic compounds (PC), 1.15 mg/g biomass from a MeOH extract	A. flavus	PC decreases the dry mass of A. flavus—1.6, 1.2 and 1.3 times (regarding glucosamine, ergosterol and protein content) Up to 56% inhibition of glucosamine	Protein content (micro-Kjeldahl method, dry weight) and ergosterol content in the mycelium	[141]
Hexane, CHCl3, EtOAc, acetone and MeOH extracts	B. subtilis, B. cereus, Enterobacter aerogenes, E. coli, K. pneumoniae, L. monocytogenes, M. luteus, P. mirabilis, P. aeruginosa, S. typhi, S. aureus, E. faecalis and Y. enterocolitica	MIC = 200–500 ppm Hexane extract IZs = 9–11 mm, acetone extract IZs = 10–12 mm, MeOH extract IZs = 11–16 mm, EtOAc IZs = 11–17 mm, highest for P. mirabilis, CHCl3 IZs = 18 mm B. subtilis (MIC at 200 ppm) and M. luteus	AWDM BMD	[68]
Proteinic, hydroethanol (hydroEtOH) and tannic extract and fraction of terpene–sterols	S. aureus, E. coli, S. typhi, Salmonella B, S. flexneri, C. albicans	All extracts inhibit S. flexneri, C. albicans Proteinic, hydroEtOH and tannic extract—S. typhi Iroteinic and hydroEtOH extracts—Salmonella B HydroEtOH extract—E. coli Tannic extract—S. aureus	-	[162]
EtOH, n-butanol, CHCl3 and water extract	M. tuberculosis	No satisfactory results	Absolute concentration method	[163]
Aqueous, EtOH and MeOH extracts	P. putida, P. fluorescens, P. aeruginosa, A. hydrophila (different strains), V. algi-nolyticus, V. parahaemolyticus, V. harveyi, V. fluvialis, V. fisheri, V. anguil-larum, E. coli (different strains) and E. tarda	EtOH extracts: no activity against E. coli strains O111 and O109, IZ = 10 mm (A. hydrophila AH1), IZ—15.6 mm (AH2 and E. coli O1 and O115). IZs = 8.3 to 10.3 mm (A. hydrophila AH3).	Single DDM	[164]
EtOH, MeOH and acetone (1:1:1) extract (21 days maceration)	Fish pathogens	The IZ = 17, 16 and 15 mm (Proteus mirabilis, Bacillus pumilus and Mammaliicoccus sciuri), IZ of antibiotics = 16–26, 16–18 or 12–20 mm	AWDM	[165]