Table 3.

Vegetable crops’ treatment with PGPB-based biostimulants and observed effects.

PGPB	Plant Species	Treatments	Observed Effects	Refs
Azospirillum brasilense Sp245	Lactuca sativa L. cv. Elisa	Seeds inoculated with 109 CFU per seed or phosphate buffer, and plants grown under salinity (0–40 mM NaCl)	Increase of plant survival of transplantation at 40 mM NaCl and enhancement of fresh and dry leaf weight, leaf area, chlorophyll and ascorbic acid content	[101]
Azospirillum brasilense Cd (DSM-1843)	Ocimum basilicum L. cv. Genovese and Red Rubin	Plants inoculated twice with bacteria 106 CFU mL−1 in the nutrient solution and/or with additional 20 mM NO3– or 8 mM SO42−	Additional nutrients but not A. brasilense enhanced fresh biomass. Inoculation increased root growth, unsaturated fatty acids, flavonoids, alkaloids and several terpene derivatives, particularly in Red Rubin.	[104]
Azospirillum brasilense and Azotobacter chroococcum (commercial mix)	Ocimum basilicum L.	Inoculation of soil or seed soaking and application to soil (2 l ha−1 with 108 CFU mL−1), bacteria + 50% N or 100% N with and without intercropping with maize	Bacteria application increased fresh and dry yield independently of cropping system. 100% N and bacteria + 50% N were both effective in increasing essential oil (methyl chavicol).	[105]
Azotobacter sp., Azospirillum sp., Bacillus licheniformis, B. megatheriumstrain Herbaspirillum sp. and Chlorella vulgaris (commercial mix)	Lactuca sativa var. crispa L. cv. Santoro and var. longifolia Lam. cv. Quintus	Application of 0.4 l of bacterial and algal mix per plant every 14 days, for a total of four treatments	Bacterial–algal mix increased the weight of both lettuce varieties but increased total carotenoid and antioxidant activity only in the cv. Quintus (romaine lettuce).	[102,103]
Azospirillum lipoferum DO12 and Brevibacillus parabrevis B50	Lycoperson esculentum Mill. cv. Menhir F1	Rhizosphere inoculation with 25 g m−2 A. lipoferum (2 × 108 CFU g−1), or B. parabrevis (3 × 109 CFU g−1)	Both bacteria increased tomato marketable yield. A. lipoferum enhanced lycopene, Vitamin C and total polyphenols; B. parabrevis increased mainly polyphenols.	[106]
Azospirillum sp. and Azotobacter sp. (commercial mix)	Solanum lycopersicum L. var. cerasiforme	Plastic bag inoculation with 1.4 l of solution prepared with 1 mL L−1 of commercial mix (1.3 × 107 CFU mL−1 of Azospirillum and 5.9 × 107 CFU mL−1 of Azotobacter) with different levels of NaCl (0, 50, 100, 150 mM)	Bacterial mix improved plant growth and yield, fruit dry matter content, pH 4.52, and TSS even under salinity.	[107]
Azospirillum sp. G. intraradices	Capsicum annuum L. (Chile Morrón, Pimiento)	Inoculation with Azospirillum sp. 104 and 106 CFU mL−1 in the nutrient solution at transplant and twice every 30 days, and 25 or 50 spores of G. intraradices at transplant with 50%/100% N and P	Higher concentration of spores and bacteria increased Vitamin C, carotenoids, total soluble solids and acidity; moreover, they improved N and P uptake at reduced N rate.	[108]
Azospirillum strains (lipoferum, brasilense, irakense and strain 21)	Foeniculum vulgare cv. Isfahan	Seed-priming with Azospirillum solution (4 mL g−1) × 12 h or microelements	Priming increased seed weight uniformly, essential oil yield, in particular α-pinene and limonene, and in strain 21 also β-pinene but not limonene.	[109]
Rhizobium laguerreae strain HUTR05	Lactuca sativa L. var. romaine	Seedling inoculation with 150 µL of bacterial suspension with 108 CFU mL−1	It increased N and P content, phenolic acids (e.g., dicaffeoyl quinic and cichoric acids) and quercetin 3-O-glucoside flavonoid.	[91]
Rhizobium laguerreae strain PEPV40	Spinacia oleracea L.	Inoculation of each seedling at the intersection between roots cotyledons with 250 μL of suspension (108 CFU mL−1)	Increase of spinach leaf number, size and weight, as well as chlorophyll and nitrogen contents.	[84]
Rhizobium laguerreae strain PEPV40 and Bacillus halotolerans SCCPVE07	Cichorium endivia L.	Plants inoculated with 2 mL of bacterial suspension (108 CFU mL−1) and irrigated with water containing 0 or 100 mM NaCl	Bacteria promoted plant development even under salinity. They increased K, Fe, Mg, N, phenolic acids (cichoric acid and caffeoyl-tartaric acid) and flavonoids (kaempferol 3-O-glucuronide).	[110]
Rhizobium legiminosarum strain TPV08 Rhizobium sp. strain PETP01	Solanum lycopersicum L. var. Cherry Capsicum annuum L. var. Verde Italiano	Seedlings inoculated with 108 CFU of each strain	TPV08 and PETP01 promoted growth of both tomato and pepper, but particularly pepper fresh weight production and tomato quality (higher N, P, K or Mg).	[90]
Rhizobium etli CE-3, R. leguminosarum SCR R. leguminosarum Semia—4088.	Solanum lycopersicum L.	Seed priming with 4 mL of each inoculum (108 CFU mL−1) kg−1 seeds + inoculation at 30 DAS with 10% of the covering of the root balls in each treatment	Rhizobia (particularly etli CE-3 and Rl SCR) improved tomato yield, probably by a more efficient acquisition of N, P and K. There were no monetary losses despite the different effects.	[111]