Oil Production from<i>Yarrowia lipolytica</i>Po1g Using Rice Bran Hydrolysate

Abstract

The purpose of this study was to produce microbial oil from <i >Yarrowia lipolytica</i> Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1&#x2013;4&#x25; v/v), reaction times (1&#x2013;8&#x2009;h), and reaction temperatures (60&#x2013;<svg style="vertical-align:-0.17555pt;width:28.025px;" id="M1" height="11.0375" version="1.1" viewBox="0 0 28.025 11.0375" width="28.025" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,11.0375)"> <g transform="translate(72,-63.17)"> <text transform="matrix(1,0,0,-1,-71.95,63.39)"> <tspan style="font-size: 12.50px; " x="0" y="0">1</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">2</tspan> <tspan style="font-size: 12.50px; " x="12.503" y="0">0</tspan> </text> <text transform="matrix(1,0,0,-1,-53.2,68.56)"> <tspan style="font-size: 8.75px; " x="0" y="0">∘</tspan> </text> </g> </g> </svg>C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3&#x25; sulfuric acid at <svg style="vertical-align:-0.27588pt;width:20.200001px;" id="M2" height="11.1625" version="1.1" viewBox="0 0 20.200001 11.1625" width="20.200001" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,11.1625)"> <g transform="translate(72,-63.07)"> <text transform="matrix(1,0,0,-1,-71.95,63.39)"> <tspan style="font-size: 12.50px; " x="0" y="0">9</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">0</tspan> </text> <text transform="matrix(1,0,0,-1,-59.45,68.56)"> <tspan style="font-size: 8.75px; " x="0" y="0">∘</tspan> </text> </g> </g> </svg>C for 6&#x2009;h. Glucose was the predominant sugar (<svg style="vertical-align:-1.09097pt;width:80.287498px;" id="M3" height="12.05" version="1.1" viewBox="0 0 80.287498 12.05" width="80.287498" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,12.05)"> <g transform="translate(72,-62.36)"> <text transform="matrix(1,0,0,-1,-71.95,63.5)"> <tspan style="font-size: 12.50px; " x="0" y="0">4</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">3</tspan> <tspan style="font-size: 12.50px; " x="12.503" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="15.62875" y="0">2</tspan> <tspan style="font-size: 12.50px; " x="21.880251" y="0">0</tspan> <tspan style="font-size: 12.50px; " x="30.907415" y="0">±</tspan> <tspan style="font-size: 12.50px; " x="42.247639" y="0">0</tspan> <tspan style="font-size: 12.50px; " x="48.499138" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="51.624886" y="0">2</tspan> <tspan style="font-size: 12.50px; " x="57.876389" y="0">8</tspan> </text> </g> </g> </svg>&#x2009;g/L) followed by xylose (<svg style="vertical-align:-1.09097pt;width:72.474998px;" id="M4" height="12.05" version="1.1" viewBox="0 0 72.474998 12.05" width="72.474998" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,12.05)"> <g transform="translate(72,-62.36)"> <text transform="matrix(1,0,0,-1,-71.95,63.5)"> <tspan style="font-size: 12.50px; " x="0" y="0">4</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="9.3772497" y="0">9</tspan> <tspan style="font-size: 12.50px; " x="15.62875" y="0">3</tspan> <tspan style="font-size: 12.50px; " x="24.655916" y="0">±</tspan> <tspan style="font-size: 12.50px; " x="35.996136" y="0">0</tspan> <tspan style="font-size: 12.50px; " x="42.247639" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="45.373386" y="0">0</tspan> <tspan style="font-size: 12.50px; " x="51.624886" y="0">3</tspan> </text> </g> </g> </svg>&#x2009;g/L) and arabinose (<svg style="vertical-align:-1.09097pt;width:72.474998px;" id="M5" height="12.05" version="1.1" viewBox="0 0 72.474998 12.05" width="72.474998" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(1.25,0,0,-1.25,0,12.05)"> <g transform="translate(72,-62.36)"> <text transform="matrix(1,0,0,-1,-71.95,63.5)"> <tspan style="font-size: 12.50px; " x="0" y="0">2</tspan> <tspan style="font-size: 12.50px; " x="6.2515001" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="9.3772497" y="0">0</tspan> <tspan style="font-size: 12.50px; " x="15.62875" y="0">9</tspan> <tspan style="font-size: 12.50px; " x="24.655916" y="0">±</tspan> <tspan style="font-size: 12.50px; " x="35.996136" y="0">0</tspan> <tspan style="font-size: 12.50px; " x="42.247639" y="0">.</tspan> <tspan style="font-size: 12.50px; " x="45.373386" y="0">0</tspan> <tspan style="font-size: 12.50px; " x="51.624886" y="0">1</tspan> </text> </g> </g> </svg>&#x2009;g/L). The hydrolysate was subsequently detoxified by neutralization to reduce the amount of inhibitors such as 5-hydroxymethylfurfural (HMF) and furfural to increase its potential as a medium for culturing <i >Y. lipolytica</i> Po1g. Dry cell mass and lipid content of <i >Y. lipolytica</i> Po1g grown in detoxified defatted rice bran hydrolysate (DRBH) under optimum conditions were 10.75&#x2009;g/L and 48.02&#x25;, respectively.