revenue growth, which included additional headcount, recruiting and relocation expense, higher compensation expense, transaction costs related to the acquisitions closed in the six months ended March 31, 2022 and Histion, an increase in sales commissions due to higher sales awards and an increase in startup costs for internal investments in new service offerings. Additionally, there was an increase in selling expenses due to an increase in travel cost as our sales and marketing teams have traveled more as the COVID-19 pandemic. During the six months ended March 31, 2022, we continued investing in internal capabilities to provide additional service offerings such as laboratory solutions, medical device pathology, biotherapeutics and genetic toxicology.
Other Income (Expense)
Interest expense for the six months ended March 31, 2022 increased to $12,375 from $713 compared to the six months ended March 31, 2021. The increase in interest expense is due primarily to the convertible senior notes and the senior term loan facility amd incremental loans, as well as various promissory notes, entered into subsequent to March 31, 2021. Interest expense for the six months ended March 31, 2022 includes approximately $2,512 of non-cash interest expense.
Other income (expense) for the six months ended March 31, 2022 was an expense of $57,866 compared to income of $179 for the six months ended March 31, 2021, due primarily to the Company recognizing a $56,714 fair value remeasurement of the embedded derivative component of the convertible notes issued in September 2021 and $877 loss on debt extinguishment.
Income Taxes
Our effective income tax rates for the six months ended March 31, 2022 and 2021 were 6.2% and (4.6)% respectively. The (benefit) expense recorded for each period was ($5,939) and $48, respectively. The benefit from income taxes for the six months ended March 31, 2022 was primarily related to a release of valuation allowance due to deferred tax liabilities established as part of the acquisition of Envigo, as well as, the impact on tax expense of certain book to tax differences on the deductibility of transaction costs, loss on fair value remeasurement of the embedded derivative component of the convertible notes, and other permanent items. The expense from income taxes in the six months ended March 31, 2021 relates primarily to certain credits that arise when deferred tax liabilities that are created by indefinite-lived assets cannot be used as a source of taxable income to support the realization of deferred tax assets for valuation allowance purposes.
Net Income/Loss
As a result of the above described factors, we had a consolidated net loss of $90,075 for the six months ended March 31, 2022 as compared to a consolidated net loss of $1,089 during the six months ended March 31, 2021.
Liquidity and Capital Resources
We believe our primary sources of liquidity are sufficient to fund our short-term and long-term existing and planned capital requirements, which include working capital obligations, capital expenditures, business development in our targeted areas, short-term and long-term debt obligations which include principal and interest payments, operating lease payments, costs associated with the integrations of our acquisitions. In addition, we have the ability to access capital markets to obtain debt refinancing for longer-term funding, if required, to service our long-term debt obligations. Further, we believe we have sufficient cash flow and liquidity to remain in compliance with our debt covenants.
Comparative Cash Flow Analysis
At March 31, 2022, we had cash and cash equivalents of $47,042, compared to $138,924 at September 30, 2021, exclusive of restricted cash.
Net cash provided by operating activities was $4,027 for the six months ended March 31, 2022 compared to net cash provided by operating activities of $4,526 for the six months ended March 31, 2021. Contributing factors to our cash provided by operations in the six months ended March 31, 2022, were noncash charges of $15,866 for depreciation and amortization, $20,300 for non-cash stock compensation expense, $56,714 for loss on fair value measurement of convertible senior notes, changes in deferred taxes of $1,907, amortization of debt issuance costs and original issue discount of $1,203, non-cash amortization of inventory fair value step-up of $6,277 and a net decrease due to changes in operating assets and liabilities of $8,725 .
Contributing factors to our cash provided by operations for the six months ended March 31, 2021 were noncash charges of $2,154 for depreciation and amortization, $460 for stock compensation expense, and a net increase in customer advances of $3,831, as a result of increasing orders. These items were partially offset by an increase of $1,927 in accounts receivable.