Evaluation of Multifarious Plant Growth Promoting Trials of Yeast Isolated from the Soil of Assam Tea (Camellia sinensis var. assamica) Plantations in Northern Thailand.

Jaturong Kumla,Supakorn Nundaeng,Saisamorn Lumyong,Nakarin Suwannarach

doi:10.3390/microorganisms8081168

Jaturong Kumla, Supakorn Nundaeng + Show 2 more

Open Access

https://doi.org/10.3390/microorganisms8081168

Copy DOI

Abstract

Some soil microorganisms, especially bacteria and mycorrhizal fungi, play a role in the promotion of plant growth. However, plant growth promotion involving yeasts in soil has not yet been extensively investigated. This study aimed to isolate and identify yeast strains obtained from soils of the Assam tea plant (Camellia sinensis var. assamica) in northern Thailand and to investigate their plant growth promoting capabilities. A total of 42 yeast strains were obtained and identified by analysis of the D1/D2 domain of the large subunit ribosomal RNA gene. We identified 35 strains of six species belonging to the phylum Ascomycota, namely Aureobasidium melanogenum, Kazachstania aquatica, Saturnispora diversa, Saturnispora sekii, Schwanniomyces pseudopolymorphus and Wickerhamomyces anomalus, and six species were determined to belong to the phylum Basidiomycota, namely Apiotrichum scarabaeorum, Curvibasidium pallidicorallinum, Papiliotrema laurentii, Rhodosporidiobolus ruineniae, Trichosporon asahii and Trichosporon coremiiforme. Seven strains were representative of potential new species and belonged to the genera Galactomyces and Wickerhamomyces. A total of 28 strains were found to produce indole-3-acetic acid (IAA) in a range of 2.12 to 37.32 mg/L, with the highest amount of IAA produced by R. ruineniae SDBR-CMU-S1-03. All yeast strains were positive in terms of ammonia production, and only eight strains were positive for siderophore production. Two yeast species, P. laurentii and W. anomalus, were able to solubilize the insoluble form of calcium and zinc. The ability to produce amylase, endogulcanase, lipase, pectinase, protease and xylanase was dependent upon the yeast species and strain involved.

Highlights

The Assam tea plant (Camellia sinensis var. assamica) is a non-alcoholic caffeine-containing beverage crop that is primarily cultivated for its leaf [1,2]
It was found that 11 strains represented six species, namely Aureobasidium melanogenum, Kazachstania aquatic, Saturnispora diversa, Saturnispora sekii, Schwanniomyces pseudopolymorphus, and Wickerhamomyces anomalus belonged to the phylum Ascomycota
We identified 24 strains of six species, namely Apiotrichum scarabaeorum, Curvibasidium pallidicorallinum, Papiliotrema laurentii, Rhodosporidiobolus ruineniae, Trichosporon asahii and Trichosporon coremiiforme in the phylum Basidiomycota

Summary

Introduction

The Assam tea plant (Camellia sinensis var. assamica) is a non-alcoholic caffeine-containing beverage crop that is primarily cultivated for its leaf [1,2]. The Assam tea plant is commonly grown in higher agricultural areas in northern Thailand at elevations of 450–1500 m above sea level. Chemical-based fertilizers are commonly used for the promotion of tea plant growth, which are known to cause environmental pollution, soil acidification, heavy metal pollution, soil compaction and changes in soil microbial populations. These fertilizers are known to be hazardous to the health of farmers as well [8,9,10]. Researchers have been interested in replacing chemical-based fertilizers with various techniques that involve the application of beneficial microorganisms, especially plant growth promoting microorganisms (PGPMs) that can support the sustainability of the agricultural industry and the environment [14,15,16]

Objectives

Methods

Results

Discussion

Conclusion